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keylight
04-14-2011, 03:08 PM
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UPDATE #2 (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2509223&viewfull=1#post2509223): I now use the incredible Tekkeon MP3450i R2.
Over 10 hours on a charge. More details in Post #201 (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2509223&viewfull=1#post2509223).
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UPDATE: In Post #152 (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2345804&viewfull=1#post2345804) guyburns put together a
GREAT summary of what we know as of 5/25/2011.
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There's a lot of information in various places on powering the GH2. I thought it might be useful to put links in one place. Hopefully this will help others in the future.

First, there's a DIY DC Adapter (DMW-DCC8) (http://www.dvxuser.com/V6/showthread.php?243760-GH2-DIY-DMW-DCC8-%28DC-adapter%29). The original idea is from Tyampel (http://www.dvxuser.com/V6/showthread.php?240093-dmw-dcc8-DC-coupler-where-is-it-in-stock&p=2261889&viewfull=1#post2261889). Another nice variation is from g.l. (http://www.dvxuser.com/V6/showthread.php?243760-GH2-DIY-DMW-DCC8-%28DC-adapter%29&p=2308383&viewfull=1#post2308383), who also had some useful tips.

33099

UPDATE: And now we know what the inside of a Panasonic DMW-DCC8 looks like. Full post here (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2351739&viewfull=1#post2351739)

34638

34639

Then, there is the DIY DC Power Source (http://vimeo.com/19591333). I made one of these and then ran it for 8 hours non-stop: Video Here (http://www.dvxuser.com/V6/showthread.php?245497-8.4v-Battery-test-results-%28timelapse%29)

33102 (http://www.dvxuser.com/V6/showthread.php?245497-8.4v-Battery-test-results-%28timelapse%29)

I used an 8.4v 4500mAh 7 cell Ni-MH flat (http://www.amazon.com/Speedpack-4500mAh-Ni-MH-7-Cell-Flat/dp/B0038LDMJE/ref=sr_1_2?ie=UTF8&s=toys-and-games&qid=1306180452&sr=1-2) battery for this test.

Below is a photo showing the bottom of the Panasonic AC Adapter (DMW-AC8PP). I metered the adapter and it runs at 8.79v. When I connect the Adapter to the camera via my DIY DC adapter, the voltage drops to 8.70. The Amperage is 740mA, even though the adapter says the output is 1.2A. See posts later in this tread for a discussion....


33005

I've scanned the manual, but the site isn't allowing me to upload. Anyone know if there's a pdf file size limit (it's approximately 1.2MB)?


Last Edit changes: Added update to the top. Removed some quotes from later in this thread, as the link in the update summarizes everything best.

g.l
04-14-2011, 04:48 PM
Thanks for collecting it all.

The one missing piece of the puzzle is what voltage the adapter actually outputs - could you test that?

keylight
04-14-2011, 04:54 PM
Thanks for collecting it all.

The one missing piece of the puzzle is what voltage the adapter actually outputs - could you test that?

Good idea. The adapter meters 8.79v. When I connect the Adapter to camera via my custom DC adapter, the voltage drops to 8.70.

Edit: The Amperage is 740mA, even though the adapter says the output is 1.2A. This seems strange. And when I try to check the Amps with the Adapter hooked up to the camera, the camera shuts off (camera runs fine otherwise).

g.l
04-14-2011, 05:07 PM
Great, this is the crucial bit. We now know that anything up to 8.8V at least is safe. Also interesting that it's rated for 1.2A.

I've suggested cheap 9V/1A adapters as suitable replacements. Looking at this all again:

- 9V is probably safe, but there's no way to be 100% sure (I will run my DC converter at around 8.6V).

Has anyone run the GH2 at 9V or higher for a long time?

- 1A is safe, but is it enough? The 1.2A rating may indicate that under exceptional circumstances the body needs a bit more juice (maybe only in tiny bursts). Or it's also possible that Panny is deliberately obfuscating so users don't look for common 9V 1A replacements.

keylight
04-14-2011, 05:29 PM
Or it's also possible that Panny is deliberately obfuscating so users don't look for common 9V 1A replacements.

Here's an interesting note from Tyampel in another thread, which may help explain the 740mA output I got on the adapter....


Thanks for posting the picture of the adapter. It is interesting to note that it differs from the one for GH1. On the GH1 it says:

INPUT/ENTREE:

110v - 240v ~ 50/60 Hz 0.3A

OUTPUT/SORTIE:

9.3V = 1.2A (DIGITAL CAMERA/APPAREIL PHOTO NUMERIQUE)

8.4V = 0.65A (CHARGE).

Perhaps the ommission is deliberate to confuse the DIY people as I don't think the cameras differ in that regard.

adolgin
04-14-2011, 05:48 PM
We have a standard product called vDoubler (http://dolgin.net/zen_dolgin/index.php?main_page=product_info&cPath=4&products_id=54) which is used to power the HD monitors and other accessories. It outputs 12V up to 2A which is more than enough power to run the GH2; we could set the output voltage to 9.2V instead of 12V and add the right connector, so it will be like the DMW-AC8PP AC adapter from the camera point of view. This adapter plate would power the GH2 camera for many hours using a DV battery (either Pan, Sony, or Canon). The problem is we do not own the camera, so can not test the configuration. If somebody is interested to be a beta tester for us, please IM directly so we can discuss logistics.

keylight
04-14-2011, 05:57 PM
Looks nice, but the price seems a bit high for a single output. The RC battery goes for about $40 and for another $5 in parts you can make a little adapter cable.

But it's something for people to keep in mind if they have a whole bunch of 7.2v batteries at their disposal. Thanks for posting it.

What would be really nice is if you came up with a solution that would allow you to plug multiple devices (that have different power requirements) into a single power source. Something like your adapter but with multiple switchable outputs (and a variety of adapter cables for different devices.


We have a standard product called vDoubler (http://dolgin.net/zen_dolgin/index.php?main_page=product_info&cPath=4&products_id=54) which is used to power the HD monitors and other accessories. It outputs 12V up to 2A which is more than enough power to run the GH2; we could set the output voltage to 9.2V instead of 12V and add the right connector, so it will be like the DMW-AC8PP AC adapter from the camera point of view. This adapter plate would power the GH2 camera for many hours using a DV battery (either Pan, Sony, or Canon). The problem is we do not own the camera, so can not test the configuration. If somebody is interested to be a beta tester for us, please IM directly so we can discuss logistics.

Svart
04-14-2011, 06:43 PM
It isn't strange that the voltage changes 90mv. That's just loss through the output filtering of the adapter. It also is NOT strange that the unit only draws 740mA from a 1.2A source. All the specs you read are always spec'd at full load. What you see is what we call "floating voltage/current". Without the load, those numbers can be all over the place.

Generally, designers just overdesign power supplies to meet instantaneous demand, or simply because they can, have certain parts available, just copied a manufacturer's design or they might have even simply reused a design from something else.

It's no attempt to obfuscate anything, I can guarantee that.

I design battery chargers amongst other power devices at my day job and this is just business as usual.

EDIT:


OUTPUT/SORTIE:

9.3V = 1.2A (DIGITAL CAMERA/APPAREIL PHOTO NUMERIQUE)

8.4V = 0.65A (CHARGE).

That difference is due to the loading of the battery vs. the loading of the camera body. The battery, when fully depleted, needs to be charged with a constant current, at a certain rate (hence the different voltage and current), until around 10-25%(depending on the cells) of it's capacity and then constant voltage charged to withing a couple mV of it's full capacity.

Allowing the cells to be charged too quickly or with too much current can alter their chemistry and damage them, aside from making them dangerous.

Anyway, I took a peek inside the GH1 charger and it has a switcher to bring down the 120vac to around 10V and then a separate battery circuit. The camera taps off the ~10v circuit. So that's why you can get different powers for the battery and body.

Svart
04-14-2011, 07:02 PM
On another note, I've been intrigued with all the fuss over second sourced batteries. I bought two ebay specials, which surprisingly claim to be LI-ion complete with protection circuitry and everything. I plan on taking one apart to see what's actually inside and if it actually is what it says it is. (I'll also use the body of it to make a DC adapter)

The second one I'll use if the first one is actually decent.

Once I get them, I'll post my findings and the link to the batteries if I think they are safe enough for use.

mslade
04-15-2011, 02:02 AM
Just an FYI...the 9 volt power supply I tried that didn't work was listed at 1200mAh. New one coming in is the one from Amazon listed in one of the threads. I believe it's rated at 2 A. Soon as I get it I'll report back.

Mark

ps Thanks for collecting all this keylight!!

guyburns
04-15-2011, 03:13 AM
You beat me to it, Keylight. I was just about to start a new thread (written offline) when I saw this one. So I hope you don't mind me pasting here.


Voltage characteristics of GH2 when powered externally
I want to find out the voltage characteristics of the GH2 when powered from an external battery. There have been several threads devoted to this topic:

1. http://www.dvxuser.com/V6/showthread.php?243760-GH2-DIY-DMW-DCC8-(DC-adapter)
2. http://www.dvxuser.com/V6/showthread.php?245022-DMW-DCC8-9.3v-or-8.4v
3. http://www.dvxuser.com/V6/showthread.php?245497-8.4v-Battery-test-results-%28timelapse%29
4. http://www.dvxuser.com/V6/showthread.php?236472-DMW-DCC8-Dc-coupler-Pearstone-NP-F975-Lithium-Ion-Battery-(7.2V-7600mAh)
5. http://www.dvxuser.com/V6/showthread.php?236137-Gh2-battery-a-joke&highlight=battery+joke

And one thread about 3rd-party batteries, which I have linked-to here because some people have suggested that 3rd party batteries won't work (and they appear to):

http://www.dvxuser.com/V6/showthread.php?242159-GH2-battery-13.99-on-Ebay

I hope that via this thread, with help from others (as I don't own a GH2 yet), that we can establish how the GH2 operates regarding voltage. This will enable users to purchase external power packs and know for certainty that they will work. Any input will be most appreciated.

Voltage required by internal electronics
The GH2 uses a 7.2 volt lithium-ion battery, consisting of two lithium-ion cells in series. Assuming there is nothing special about this particular lithium-ion battery, it will have a voltage range from 8.4 volts (fully charged) to about 6.6 volts, below which it does not have much capacity left, and below which it should not be discharged anyway.

The upper limit is definite, but I am unsure about the lower limit (some lithium-ion batteries are taken as low as 2.7 volts/cell). The lower limit is probably controlled by the camera. i.e. it will purposely switch off to protect the battery when the voltage is too low, and not because the electronics simply stop working.

It has been clearly shown (see Thread 3) that the voltage must be above 8.4 volts when the GH2 is powered via the DCC8 adaptor, otherwise it turns off. I want to determine why that happens and if it is possible to overcome that limitation, because it would be desirable to operate the GH2 from 6.6 volts to 8.4 volts to optimise the battery efficiency. For example:


• The GH2 could then be powered by an external, large-capacity, 7.2 volt lithium-ion battery. At present, this is not possible because of the 8.4 volt lower-limit constraint. To run the GH2 from an external lithium-ion battery requires at least a 3-cell battery (10.8 volts) and circuitry to convert that voltage to a lower voltage. In doing so, some of the battery power is wasted.

• Or you could use 6 NiMH cells, instead of 7 or 8 as users are doing now. Depending on the exact lower-voltage cutoff point, 6 cells may not discharge their full capacity, but would come close if the cutoff is 6.6 volts (guessed). Seven cells would allow 100% of their capacity to be used.

As things stand, using 7 NiMH cells wastes a significant amount of the battery's capacity because the GH2 will turn off when the battery pack reaches 8.4 volts (1.2 volts per cell) – and NiMH cells still have a lot of capacity left at 1.2 volts. I have just tested an Eneloop 2000 mAh battery. I fully charged it, then measured its capacity down to 1.0 volts (2020 mAh), then charged it again. When I discharged it to 1.2 volts it provided only 1180 mAh, 53% (1080/2020) of the available capacity of the battery.

If a way can be found to power the GH2 from less than 8.4 volts (as is done by the original battery), users would then have a choice:


1. Use a 7.2 volt Lithium-ion battery at 100% efficiency;

2. Use an 8.4 volt (7-cell) NiMH pack at 100 % efficiency (presently ~50% efficiency);

3. Use a 7.2 volt (6-cell) NiMH pack at an unknown efficiency (it would cut off early).

To be able to work out what the GH2 is doing to external power, and whether it is possible to bypass its interference with external power supplies, I need answers to the following questions. I'd like actual test results if possible.

Q1: Using the DCC8, will the GH2 turn ON and stay on if the voltage is less than 8.4 volts?


A simple way to perform this test is to use 6 x AAs in good condition that have been fully charged – but measure the voltage first to make sure it is less than 8.4 volts to start with. Using a regulated AC-DC power supply would be better, in which case set it to 7.2 volts.

The obvious answer to this question is "no", because it has already been established that the GH2 turns off below 8.4 volts. But that may not be the correct answer. There is a possibility that if the GH2 sees less than 8.4 volts at turn-on, it assumes a battery is in place and maybe it won't turn off.


Q2: What is it about the original battery, and 3rd party batteries, that ensures the GH2 sees them as batteries? A thought experiment: buy a 3rd party battery, open the case and remove the chemistry, then run two wires from the terminals to an external battery: would the GH2 then work as if it was running from an internal battery?


Q3. What is the function of those two extra terminals on the original battery? Do they simply transmit capacity data to the GH2, or are they somehow involved in telling the GH2 that "Hey, we've got a battery here".


Q4. Do 3rd-party batteries have those two extra terminals, and are they connected to each other or to the other terminals? If so, I want to work out their "Thevenin equivalent circuit". That way I should be able to mimic their function, so that the "less than 8.4 volts turn-off" is not triggered when running from an external supply.


One way to find out what is connected to the terminals is to pull the battery apart (I've ordered a battery and charger from HK, and that's what I'll be doing when the battery arrives and I have finished testing it). But there is a non-destructive way, if you are keen to help. You'll need a digital voltmeter, a 1 kohm resistor, and a 3rd-party battery. Measure the open-circuit voltage between the 0V terminal and all the others (3 measurements); the same for the +ve terminal (3 measurements); and now repeat by putting the 1 kohm resistor between the same set of terminals (6 measurements) and measuring the voltage again. Then measure the voltage across the two extra terminals, with and without the resistor. Let me know those 14 measurements and I may be able to work out what's inside the battery. For each measurement, I have to know which terminal the meter's "ground" plug was connected to and whether the reading was positive or negative.


Q5. Other than not providing capacity readout for the GH2, do 3rd-party batteries function identically to the original battery?


Q6: Instead of spending several hours making a fake DCC8, why don't experimenters simply buy an el-cheapo battery from HK for $15 (free postage) and replace the internals?


Q7. Does the DCC8 have the extra two terminals?


Q8. Are the power terminals of the DCC8 connected straight through, or are there components inside? To find out without pulling it apart, power up the DCC8 outside the camera, take the Thevenin measurements as described in Q4, and pass them on to me. I'll see what I can work out.


Looking forward to any replies in the hope of being able to extract maximum energy from external batteries. Feel free to gmail me at gdburns if you have any questions.

daihard
04-15-2011, 04:07 AM
I have a nice source maybe someone can test out.
You can get very cheap LI-ion cells of different sizes, volts, and amps.
http://www.dealextreme.com/c/batteries-400?page=1&pagesize=52&pagesort=popularity
I awaiting a shipment of a few cells for my high powered LED lights. They come in protected and unprotected configurations so you cant overcharge or discharge.

Can anyone verify if this sounds safe to try with the batteries I do have?
TrustFire TR 18650 2500mAh 3.7V Batteries (2-Pack)
So its about 7.4V LI-ion that would be going into my GH2
The cells are small and slim so I think in the future, someone can make a battery grip with these very easily.

Hope this helps.

Dai-Lon
http://www.dailonweiss.com/
http://www.kristinaweiss.com/Magyar/

daihard
04-15-2011, 04:17 AM
Just a thought for the "Wood" adaptor, has anyone thought of doing a plaster mold? Then casting the battery outta.... say hot glue gun rubber or something equivalent? I'm just looking round the house to see what I have available...

g.l
04-15-2011, 11:05 AM
So its about 7.4V LI-ion that would be going into my GH2
The cells are small and slim so I think in the future, someone can make a battery grip with these very easily.

Unfortunately this won't work. Only official Panny batteries will work at 7.2V (2x3.6V) as they communicate with the body to ID themselves.

The only option is using AC adapter voltages of 8.5V-8.8V (known safe), or maybe 9V (probably safe). People have been using up to 10V, but I really would avoid pushing it that far.

Also note that rechargeable batteries usually put out more voltage when they're fully charged than they're rated for. The bundled Panny battery 7.2V battery actually outputs ~8.3V fully charged. So you need to take that into account too.

mslade
04-15-2011, 11:40 AM
Hey Guy....don't know if this helps.....I have a home made adapter. With a radio shack 9v 1200mAh power supply the cam would not power up.....nothing, not even a warning. Measured 9.3 v at the adapter. If I connect the OEM battery to my home built adapter it flashes on and I get the "This battery can not be used". warning. That same battery will power up the cam if placed in the cam. Waiting on a power supply that others have used with success.

Here are some voltages on a twice charged brand new battery fresh off the charger..... the terminals from the inside to the outside of the battery are labeled +, T, D, and -. Pos lead on +, neg lead on - is 8.26v move neg lead to D it flashes 8.26v but then drops to 7.61v in about 5 seconds. neg lead to T 8.26v Neg lead on - pos lead on T is 0.00v move pos lead to D 0.062v Wish I had a resistor I could do more....

Mark

Eugenio
04-15-2011, 11:49 AM
" 1. Use a 7.2 volt Lithium-ion battery at 100% efficiency; "

The GH2 would work 100% with the battery NP F970 Sony Litihum Ion 7.4V / 6600mAh ?

g.l
04-16-2011, 02:29 AM
The GH2 would work 100% with the battery NP F970 Sony Litihum Ion 7.4V / 6600mAh ?

No, read my above post.

g.l
04-16-2011, 02:30 AM
Hey Guy....don't know if this helps.....I have a home made adapter. With a radio shack 9v 1200mAh power supply the cam would not power up.....nothing, not even a warning. Measured 9.3 v at the adapter.

9.3V worked fine for me on two bodies. Are you sure you got the polarity right? And that the contacts were definitely in the right place?

guyburns
04-16-2011, 02:31 AM
Only official Panny batteries will work at 7.2V (2x3.6V) as they communicate with the body to ID themselves.

Not strictly correct according to: http://www.dvxuser.com/V6/showthread...-13.99-on-Ebay

3rd-party batteries do seem to work and I'd like to know what they did to make them work.

guyburns
04-16-2011, 02:59 AM
Hey Guy....don't know if this helps.....I have a home made adapter. With a radio shack 9v 1200mAh power supply the cam would not power up.....nothing, not even a warning. Measured 9.3 v at the adapter. If I connect the OEM battery to my home built adapter it flashes on and I get the "This battery can not be used". warning. That same battery will power up the cam if placed in the cam. Waiting on a power supply that others have used with success.

Here are some voltages on a twice charged brand new battery fresh off the charger..... the terminals from the inside to the outside of the battery are labeled +, T, D, and -. Pos lead on +, neg lead on - is 8.26v move neg lead to D it flashes 8.26v but then drops to 7.61v in about 5 seconds. neg lead to T 8.26v Neg lead on - pos lead on T is 0.00v move pos lead to D 0.062v Wish I had a resistor I could do more....

Mark

Thanks for the voltages. I'll pull some circuit theory out of my old head and see if I can deduce anything about the internals.

As for the Radio Shack power supply not working: the important thing is not the voltage at no-load, but the voltage when loaded. I'm guessing here, but the GH2 could be doing this:


1. When the on-switch is pressed, the GH2 checks the voltage at its power terminals, before most of the electronics are turned on.

2. If it finds greater than 8.4 volts it thinks to itself: "Power adaptor" and sets a "power-adaptor flag" internally that switches off the camera if the voltage drops below 8.4 volts.

3. If it finds less than 8.4 volts, and the required signals on certain of the pins are present (signals that I'm trying to determine), it thinks to itself: "Battery", sets a "battery flag" internally, and this allows the camera to operate at lower voltages.

4. The GH2 then tries to fire up. If the "power adaptor flag" has been set and the voltage at anytime drops below 8.4 volts, the GH2 presents a message and then shuts off. If the "battery flag" has been set, the GH2 won't turn off till a much lower voltage, the value of which is not yet determined.

In your case, the only reason I can think of that the camera just died is that when the GH2 tried to give you the message by turning on the screen, the voltage out of your supply dropped below the minimum required for the GH2 to even turn on.

I'll explain this a bit further. If the GH2 has a large inrush current when it is first turned on, you can expect a large voltage drop in the power supply (if it is not well-regulated) and further drops in the connecting leads and contacts. I don't know if the GH2 has a spike in current when turned on, but the two other digital cameras I own certainly do have: a Kodak DX3500 (2001 vintage) and a Nikon Coolpix 7600 (2005 vintage). I have just tested the Coolpix (2 AAs), and these are the current readings at turn on:

0-1 second: ~400 mA

1-4 seconds: 1000-1200 mA

4+ seconds: 750 mA.

That middle section (electronics and monitor turning on, lens being moved out ) is the killer for anything other than good-quality batteries or power supplies. My Eneloops can handle it, even when they are nearly exhausted, but my other rechargeables, well, if newly charged they may work for 10 or 20 turn-ons, but then the camera won't fire up. There's still plenty of life in the batteries, but the voltage drops so low during attempted turn-on, that the camera turns off.

You can test your power supply, but you'll need to attach it to something that draws about 10 Watts (about 1 Amp) and measure the voltage. If there is an electronics shop handy, buy yourself a 10 ohm, 5W resistor (about 50 cents). Just don't leave it on for more than about 10 seconds. Or jump up to a 10W version for about $2 and test all day long.

mslade
04-16-2011, 10:08 AM
9.3V worked fine for me on two bodies. Are you sure you got the polarity right? And that the contacts were definitely in the right place?

Positive about the polarity (no pun intended)

Mark

g.l
04-16-2011, 11:02 AM
Thanks for the voltages. I'll pull some circuit theory out of my old head and see if I can deduce anything about the internals.

I bet it's something really simple that just produces a certain voltage signature.


I'm guessing here, but the GH2 could be doing this:<snip>

Yes, absolutely. The body can clearly accept a fairly wide voltage range (whatever the bundled batteries' empty cutoff point is -> at least 9V). That's not something I've seen before on a device (not because it can't be done but because it costs a bit more to implement) - but it allows them to implement purely software-goverened voltage ranges to protect their accessories. But (lucky for us) it also makes it more tolerant to sticking the wrong thing in there - usually electronic devices just die if you get it even slightly wrong.

And good point about the inrush current.

mslade
04-16-2011, 12:33 PM
Let me throw this out here. Why does a battery that has been partly used up and measures only 7.1v fire up the camera??

Mark

keylight
04-16-2011, 12:48 PM
Let me throw this out here. Why does a battery that has been partly used up and measures only 7.1v fire up the camera??

Mark

I'm thinking guyburns and g.l. probably have it right. The camera operates on a wide range of voltages. We don't really know what the high and low ends are. Next time I fully deplete the internal battery, I'll meter it before recharging. That would give us the bottom end.

keylight
04-16-2011, 01:03 PM
I'm guessing here, but the GH2 could be doing this:

1. When the on-switch is pressed, the GH2 checks the voltage at its power terminals, before most of the electronics are turned on.

2. If it finds greater than 8.4 volts it thinks to itself: "Power adaptor" and sets a "power-adaptor flag" internally that switches off the camera if the voltage drops below 8.4 volts.

3. If it finds less than 8.4 volts, and the required signals on certain of the pins are present (signals that I'm trying to determine), it thinks to itself: "Battery", sets a "battery flag" internally, and this allows the camera to operate at lower voltages.

4. The GH2 then tries to fire up. If the "power adaptor flag" has been set and the voltage at anytime drops below 8.4 volts, the GH2 presents a message and then shuts off. If the "battery flag" has been set, the GH2 won't turn off till a much lower voltage, the value of which is not yet determined.


Yes, absolutely. The body can clearly accept a fairly wide voltage range (whatever the bundled batteries' empty cutoff point is -> at least 9V). That's not something I've seen before on a device (not because it can't be done but because it costs a bit more to implement) - but it allows them to implement purely software-goverened voltage ranges to protect their accessories. But (lucky for us) it also makes it more tolerant to sticking the wrong thing in there - usually electronic devices just die if you get it even slightly wrong.

I wonder if it's possible (although maybe not all that desirable) to make a dc adapter that has a chip inside that would send a signal to the camera once the external battery hits 8.4v. The camera might shut off for a moment, but at least you would get some extra power.

Of course, we have no idea how the 2 extra contacts on the battery are used. It could be that the camera just checks to see if they are present (pass current through them to see if it completes a circuit). In which case, adding a little piece to bridge those two contacts when an external battery drops below 8.4v would be a fairly simple thing to do. I suspect it's a bit more complicated than that though....

I once hacked open a battery for my Nikon after it wouldn't hold a charge anymore, and the circuitry was pretty damn intimidating. Played with making an external power source using the old shell as an adapter, but could never get the right voltages out of the contacts. Someday when the GH2 battery stops taking a charge (hopefully after replacement batteries become widely available) I'll hack it open too......

g.l
04-16-2011, 02:21 PM
I wonder if it's possible (although maybe not all that desirable) to make a dc adapter that has a chip inside that would send a signal to the camera once the external battery hits 8.4v. The camera might shut off for a moment, but at least you would get some extra power.

You mean it would pretend to be an internal battery just as it hits the threshold? I think that would be tricky. The threshold is going to be a (small) voltage range, not just an exact value, due to inaccuracies/fluctuations/component tolerances etc. So even if you could do it, you may have to wait 'till the external voltage crosses the lower part of that range before the camera would accept it as an official battery, creating a temporary 'dead zone'. I think a firmware hack is a better bet to remove the battery protection completely.

I will run my bodies off 12V Li-on batteries (that way I can also drive my portable HDMI screens). I'll be using a DC->DC converter circuit to set a precise output voltage (I guess around 8.6V). They accept a wide range of input voltages, but keep the output voltage consistent. That's exactly what the bodies are doing of course.

keylight
04-16-2011, 09:27 PM
You mean it would pretend to be an internal battery just as it hits the threshold?

Yeah, something like that. It's an idea, but really not all that useful. Your idea however:


I will run my bodies off 12V Li-on batteries (that way I can also drive my portable HDMI screens). I'll be using a DC->DC converter circuit to set a precise output voltage (I guess around 8.6V).

That is quite useful. I've been using one of these (http://www.amazon.com/s?ie=UTF8&keywords=B002CG001E&tag=keylightfilms-20&index=blended&I1=Go&link_code=qs&I1.x=10&I1.y=13) when I shoot long timelapse shots. It's really heavy but the power goes on and on.... It's something I'll probably want to get. Of course, I can always just plug the AC adapter into the 12v battery's AC outlet, but that's somehow a lot less elegant. Going from 12v DC to AC and then back to DC.

Are you making your own circuit or do you have a good source for something off the shelf? I found this (http://www.amazon.com/s?ie=UTF8&keywords=B003Z2W9CC&tag=keylightfilms-20&index=blended&I1=Go&link_code=qs&I1.x=10&I1.y=3) but I'd rather have something single purpose and locked into one voltage.

Eugenio
04-16-2011, 10:48 PM
Using a Ni-MH 12v + voltage regulator for an output of 8.6 V would be functional, efficient and safe?

Ni-MH 8.4 V versus NI-MH 12v + voltage regulator, pros and cons?

Batteries:

http://portuguese.alibaba.com/product-gs/nimh-battery-pack-with-12v-voltage-and-42a-maximum-discharge-rate-348402030.html

http://portuguese.alibaba.com/product-gs/nimh-f-7000mah-12v-rechargeable-battery-pack-203100850.html

I am Brazilian and I have little understanding of English, who helps me is the google translator, sorry for the mistakes and the lack of understanding.

I'm learning a lot here and want to ride my kit

Thanks.

guyburns
04-17-2011, 12:22 AM
Eugenio: The batteries you posted would have plenty of oomph. Then you'll need a regulator, and unless you have the technical knowledge to build one, you would require one that has 8.6 - 9.2 volts output, rated at 1.2 amps. Such an off-the-shelf device may be hard to come by, though I haven't looked into that yet. You may get away with a regulator rated at less amps, say 1.0 amps, but the Pansonic power supply does say 1.2 amps. The camera may not draw that much, but my guess is that under worst-case conditions the GH2 may draw up to 1 amp – and 1.2 amps allows a margin of safety.

I'm toying with the idea of experimenting with one of these:

http://focus.ti.com/lit/ds/symlink/ptn78000w.pdf

Costs less than $20 from places like digikey or RS Components. It provides up to 1.5 amps output, would require higher than ~11 volts input to give 8.6 volts output, ~90% efficient, and is easily adjustable with one resistor (see page 10 of the PDF). But building such a unit would require a certain amount of expertise.

guyburns
04-17-2011, 12:28 AM
Let me throw this out here. Why does a battery that has been partly used up and measures only 7.1v fire up the camera??

Mark

Because the GH2 internally has a cutoff voltage that is probably around 6.6 volts, maybe even as low as 6.0 volts.

guyburns
04-17-2011, 12:41 AM
Next time I fully deplete the internal battery, I'll meter it before recharging. That would give us the bottom end.

Not quite the bottom end, but it would be useful to know the battery voltage when you pull it out. The actual cutoff point would be difficult to measure accurately, because you would have to monitor the voltage at the GH2's power terminals as the voltage dropped, and note when it turned off. You might get an idea of the lower cutoff voltage by running the battery down so that the camera turns off, then pulling the battery out and measuring its voltage. But the problem is that the battery voltage will recover a certain amount -- it will immediately increase as soon as the load is taken off. i.e the battery volts will decrease… 6.8, 6.7, 6.6 … then the camera might turn off at 6.6, but by the time you pull it out it may have recovered to 6.9.

As a real example, I just loaded a Li-ion 860 mAh battery (4.03 volts unloaded) with 400 mA. The battery (not fully charged) dropped to 3.65 volts in about 30 seconds. I removed the load, waited 5 seconds, and the voltage had risen over that time to 3.92 volts, and still rising.

guyburns
04-17-2011, 12:58 AM
[/INDENT]


I wonder if it's possible (although maybe not all that desirable) to make a dc adapter that has a chip inside that would send a signal to the camera once the external battery hits 8.4v.

An interesting approach, but there is an easier way. My idea is to have a DC adaptor that fools the GH2 into thinking there is a battery in place all the time. The Chinese makers of the 3rd-party batteries have worked out what to put inside their batteries to fool the GH2. Now what they should do is manufacture a battery but without the chemicals. inside there would be a few components, and two wires leading from the power terminals to a socket on the rear for connection to the outside world. A battery without the li-ion; A DCC8 that does not cutoff at 8.4 volts.

I have asked the HK supplier who sold me a battery and charger to ask his supplier to make such a device. He has not responded yet. I think it's about time I sent messages to all the eBay sellers of 3rd-party batteries, asking them the same thing. But their English is not the best. Anyone here with the ability to write in Chinese?

If any of the Chinese manufacturers are reading this, here's how you do it.


1. Manufacture battery case without the chemicals, but with certain components connected to the T and D terminals to fool the GH2 into thinking it is a battery.

2. Mould a power socket onto the rear to which any battery of any chemistry from 12-32 volts can be connected.

3. Use this fixed 9-volt switching regulator (efficiency > 92%) between the power socket and terminals + and -.

http://products.cui.com/adtemplate_child.asp?brand=v-infinity&p=326824&c=972438&catky=328060&subcatky1=521999&subcatky2=568080#. Cost ~$5 each in bulk.

4. Place ad on eBay: "Superior DCC8 replacement. Works by any voltage more than 12 volts. 95% efficient. Only $25. Shipping free"

I guarantee you'll sell thousands and become rich!

Edited: A 7.2-volt switching regulator would be better than a 9.0 volt regulator as it would output the same nominal voltage as the battery.

guyburns
04-17-2011, 01:34 AM
Are you making your own circuit or do you have a good source for something off the shelf? I found this (http://www.amazon.com/s?ie=UTF8&keywords=B003Z2W9CC&tag=keylightfilms-20&index=blended&I1=Go&link_code=qs&I1.x=10&I1.y=3) but I'd rather have something single purpose and locked into one voltage.

That DC-DC adaptor has no technical information on the Amazon website, and I couldn't track down any. However, I did track down a similar looking device with technical information. This particular unit supposedly provides a regulated 2000 mA at various output voltages:

http://www.jaycar.com.au/productView.asp?ID=MP3038

Eugenio
04-17-2011, 09:22 AM
Thanks for the information !

I'll look for an electronic technician to build my voltage regulator, fixed output of 8.6 V and 1.2 mah

If I find an electronic technician qualified to do this will be my salvation.

Buying at B & H three original batteries and sending to Brazil ..:

Three Battery: $ 60 unit
+
Shipping: $ 50
______________________

$ 230

+

Abusive tax: 78%
______________________

Total: $ 410

g.l
04-17-2011, 09:38 AM
I'm toying with the idea of experimenting with one of these:

That's exactly what I'm working on, except I'm using the 3A version (PTN78060W) as I'm driving two bodies (stereo rig). I have my free samples from TI, but you need to supply some additional parts (2 caps & a resistor).

Similar simpler versions do exist on Ebay (everything included, just adjust a trimmer to set your output voltage). I have no idea how reliable they are, but they may be fine. They're called DC DC 'step-up' / 'boost' converters (smaller V in, higher V out), or 'step-down' / 'buck' (http://cgi.ebay.co.uk/LM2596-DC-Step-Down-Converter-Adjustable-Power-Module-/190521645543?pt=LH_DefaultDomain_0&hash=item2c5bf999e7) (higher V in, smaller out). Make sure they handle your input V range (max & min charged state), and that you will input enough voltage for the desired output voltage (the step-downs typically need a bit more voltage going in than coming out).

You can check out my preferred 12V batteries (http://www.dvxuser.com/V6/showthread.php?221553-GH1-Stereoscopic-Rig-Collaboration&p=2243171&viewfull=1#post2243171) in the 3D rig thread, they are cheap, small, cased, and can be charged just by plugging the AC adapter they come with in. And Li-ons are smaller/lighter than Nimh etc. I've got mine already, but I haven't been able to test them yet.

g.l
04-17-2011, 10:07 AM
An interesting approach, but there is an easier way. My idea is to have a DC adaptor that fools the GH2 into thinking there is a battery in place all the time. The Chinese makers of the 3rd-party batteries have worked out what to put inside their batteries to fool the GH2. Now what they should do is manufacture a battery but without the chemicals. inside there would be a few components, and two wires leading from the power terminals to a socket on the rear for connection to the outside world. A battery without the li-ion; A DCC8 that does not cutoff at 8.4 volts.

It's a good idea, but do we know that the body would accept an 'official' battery that puts out more than the official voltage? I think it's likely it will detect that as a dangerous situation (assuming a battery malfunction) and shut down.

... or (reading your post again), did you mean with a DC converter built-in?

g.l
04-17-2011, 10:12 AM
That DC-DC adaptor has no technical information on the Amazon website, and I couldn't track down any. However, I did track down a similar looking device with technical information. This particular unit supposedly provides a regulated 2000 mA at various output voltages:

http://www.jaycar.com.au/productView.asp?ID=MP3038

I found these when I did my research too. They have 9V outputs - if 9V is safe (for longer periods) then they would probably work with 12V batteries. Lots on Ebay.

Eugenio
04-17-2011, 12:24 PM
Last question:

If I use a voltage regulator programmed to 8.6 V, a battery of 8.4 (9.8 v in a state of total load), the GH2 will work for a while to get interesting, at least 5 hours?

When my adaptation is ready and tested, I'll post pictures and results.

g.l
04-17-2011, 12:43 PM
If I use a voltage regulator programmed to 8.6 V, a battery of 8.4 (9.8 v in a state of total load)[/b]

The step-down DC voltage converters typically need an extra 2 (or more) Volts in than they output. So chances are you need to input at least 8.5V + 2V = ~10.5V (maybe more). Also note that many batteries give out a higher voltage than rated when fully charged, and lower as they run out - so you need to take that into account too.


the GH2 will work for a while to get interesting, at least 5 hours?If the battery has a high enough mah (ma per hour) rating, sure :). The bundled battery is 1200mah @ 8.4V, which means 'you can draw 1.2A for an hour before it dies' (if you take less, it lasts longer). So that gives you an idea.

Note that amps go down as voltage goes up, and vice versa. The formula: Watts = Volts * Amps.

So 1.2A (1200ma) @ 8.4V = (1.2 * 8.4) 10.08 Watts

So the equivalent A in 12V = 10.08W / 12V = 0.84A (840ma)

So for example, a 1200mah rated 12V battery will actually give you 1714mah if you convert it to 8.4V (more than the official battery). But you also loose around 5-10% in the conversion (depending on the efficiency of the converter), so it's more like 1600mah.

Eugenio
04-17-2011, 05:32 PM
Eugenio: The batteries you posted would have plenty of oomph. Then you'll need a regulator, and unless you have the technical knowledge to build one, you would require one that has 8.6 - 9.2 volts output, rated at 1.2 amps. Such an off-the-shelf device may be hard to come by, though I haven't looked into that yet. You may get away with a regulator rated at less amps, say 1.0 amps, but the Pansonic power supply does say 1.2 amps. The camera may not draw that much, but my guess is that under worst-case conditions the GH2 may draw up to 1 amp – and 1.2 amps allows a margin of safety.

I'm toying with the idea of experimenting with one of these:

http://focus.ti.com/lit/ds/symlink/ptn78000w.pdf

Costs less than $20 from places like digikey or RS Components. It provides up to 1.5 amps output, would require higher than ~11 volts input to give 8.6 volts output, ~90% efficient, and is easily adjustable with one resistor (see page 10 of the PDF). But building such a unit would require a certain amount of expertise.


I managed to find the voltage regulator ptn78000w here in Brazil.

I do not have the least experience with electronics, I think of buying the components and find a professional to make adjustments and fit the puzzle.

Buy ptn78000w and make adjustments with a good professional is an alternative with an acceptable degree of certainty?

Or build a voltage regulator of the zero point is more reliable?


I'll get more information about the ptn78000w.

guyburns
04-17-2011, 09:47 PM
Eugenio: I wouldn't recommend asking someone to make up a special unit for you using the components I mentioned. Building electronic devices is fine if you are a hobbyist, but it is very time consuming and you will rarely up with a device as compact, economical or as neat looking as a manufactured device. For me to design and build a regulated supply for the GH2 would take several hours and cost three times as much as an off-the-shelf device (if available). I'd have to buy the components, breadboard the design to test it first, then solder them on a circuit board which I'd have to make, add leads, mount everything in a case, and provide external connections. I suggest in your case to stick with off-the-shelf components bought locally.

For instance, if weight is not a problem, why not use a sealed lead-acid battery? Robust, reliable, lasts for years, cheap and readily available. As an example, here is a battery that would power a GH2 for a dozen hours or more and costs about $30 here in Australia: http://www.jaycar.com.au/productView.asp?ID=SB2486. Battery shops, motorcycle shops, all sorts of shops sell them. Another benefit, to charge it you could use a cheap 12-volt charger designed to charge car batteries.

You'll need a good regulated DC-DC converter, of course, and that's the tricky part. Automotive shops may sell them. Probably sell the battery too. And a digital multimeter if you haven't got one. Take a 10-ohm, 10 Watt resistor with you and do this:

1. Hook the regulator to the battery, the resistor to the regulator, and the meter to the resistor. Check the voltage across the resistor. If it is greater than 8.6 volts, buy battery, buy regulator.

guyburns
04-17-2011, 10:17 PM
It's a good idea, but do we know that the body would accept an 'official' battery that puts out more than the official voltage? I think it's likely it will detect that as a dangerous situation (assuming a battery malfunction) and shut down.

... or (reading your post again), did you mean with a DC converter built-in?

Yes, you are probably right. A higher voltage from an official battery might cause the camera to shut down. Or it might wreck the camera electronics. The modified DCC8 that I am suggesting would of necessity (see below) have a regulator built in so that it outputs 7.2 volts.

I've been trying to think of a reason why Panasonic requires external supplies to be greater than 8.4 volts. The only one I have come up with is: for protection purposes. When running of the internal battery, there is virtually no possibility that an error can be made. The polarity is correct, the voltage cannot be too high. So the internal electronics can be powered straight from the battery. However, Pansonic may have decided that for external supplies, they had better build in some protection against wrong polarity and high voltage. They don't want cameras being returned because someone has applied reverse polarity, for example, and destroyed the internals. Such protection circuitry may require an overhead of a few volts. A possibility is that when an applied voltage of > 8.4 volts is detected, protection circuitry inside the GH2 is switched on, and that protection circuitry unavoidably causes a voltage drop of, say, 2 volts. i.e. for an external supply, maybe the GH2 isn't purposely cutting off at 8.4 volts, but it cuts off because the external 8.4 volts - 2 volts (assumed voltage drop in protection circuitry) falls below that required by the GH2.

If that is the case, it may be absolutely necessary to use a 7.2 volt regulator inside a modified DCC8, to prevent voltages higher than 8.4 volts (known to be safe) being sent directly to the camera internals, and to protect against user error (external supply being of wrong polarity, or voltage too high).

Eugenio
04-17-2011, 10:35 PM
This is the battery:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280538988771&ssPageName=STRK:MEWAX:IT # ht_6747wt_698

This is the regulator:

http://br.mouser.com/search/ProductDetail.aspx?qs=sSOk4GDDv7zfoj5u0nVBmg%3D%3D

This two intens in the hands of a good professional electronics, along with the instructions here (regulator output at 8.6 v 1.5 mah), I am well served?

Thanks, I'm looking forward to starting construction.

mslade
04-18-2011, 12:56 AM
Because the GH2 internally has a cutoff voltage that is probably around 6.6 volts, maybe even as low as 6.0 volts.

I guess what raised my question is the fact that putting less than 8.4v to the camera results in it not working.

Mark

chon
04-18-2011, 03:09 AM
Similar simpler versions do exist on Ebay (everything included, just adjust a trimmer to set your output voltage). I have no idea how reliable they are, but they may be fine. They're called DC DC 'step-up' / 'boost' converters (smaller V in, higher V out), or 'step-down' / 'buck' (http://cgi.ebay.co.uk/LM2596-DC-Step-Down-Converter-Adjustable-Power-Module-/190521645543?pt=LH_DefaultDomain_0&hash=item2c5bf999e7) (higher V in, smaller out). Make sure they handle your input V range (max & min charged state), and that you will input enough voltage for the desired output voltage (the step-downs typically need a bit more voltage going in than coming out).
Virtually identical module with free shipping:
http://cgi.ebay.com/LM2596-DC-DC-Step-Down-Adjustable-Power-Supply-Module-/320570868469

UK link:
http://cgi.ebay.co.uk/LM2596-DC-DC-Step-Down-Adjustable-Power-Supply-Module-/320570868469

chon
04-18-2011, 03:34 AM
How about this, a Li-ion battery with a 9V 8.5Ah output, comes with charger:
http://cgi.ebay.com/5V-9V-12V-DC-Rechargeable-Li-ion-battery-CCTV-cam-/160438173336

I'm guessing the 5V and 9V outputs are regulated since they're not multiples of 3.6V.

guyburns
04-18-2011, 04:26 AM
This is the battery:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280538988771&ssPageName=STRK:MEWAX:IT # ht_6747wt_698

This is the regulator:

http://br.mouser.com/search/ProductDetail.aspx?qs=sSOk4GDDv7zfoj5u0nVBmg%3D%3D

This two intens in the hands of a good professional electronics, along with the instructions here (regulator output at 8.6 v 1.5 mah), I am well served?

Thanks, I'm looking forward to starting construction.

Regarding the battery: I think you will be disappointed. You get what you pay for. I doubt very much that a 12 volt, 6.8Ah Li-ion battery costing $30 (with charger) will retain its capacity after more than a few discharges. But it's only $30 so you haven't lost much.

As for the DC-DC regulator, the Texas Instruments requires extra components and someone to set it up for you: tell them 8.6 volts. No other specification is required. You may be better off with the cheap regulators mentioned by Chon (post above). It appears to have an on-board voltage adjustment that you could do yourself.

Eugenio
04-18-2011, 07:14 AM
Regarding the battery: I think you will be disappointed. You get what you pay for. I doubt very much that a 12 volt, 6.8Ah Li-ion battery costing $30 (with charger) will retain its capacity after more than a few discharges. But it's only $30 so you haven't lost much.

As for the DC-DC regulator, the Texas Instruments requires extra components and someone to set it up for you: tell them 8.6 volts. No other specification is required. You may be better off with the cheap regulators mentioned by Chon (post above). It appears to have an on-board voltage adjustment that you could do yourself.

Regarding the battery, thanks for the tip, I'll keep searching and buy a good reference.

Regarding the voltage regulator, I have a professional who can configure it for me. I cherish the very security of GH2, and I want a good voltage regulator. In his opinion the voltage regulator PTN78000WAH is safer than the alternatives Chon?

chon
04-18-2011, 07:38 AM
Regarding the battery, thanks for the tip, I'll keep searching and buy a good reference.

Regarding the voltage regulator, I have a professional who can configure it for me. I cherish the very security of GH2, and I want a good voltage regulator. In his opinion the voltage regulator PTN78000WAH is safer than the alternatives Chon?
Don't worry, the chip (http://www.national.com/mpf/LM/LM2596.html) has both overcurrent limitation and overheating cut off. A bit overkill, but you could get a 5A regulator if you feel the need:
http://cgi.ebay.com/LM338K-DC-AC-6V-30V-Out-DC-4-5V-28V-5A-Converter-/290547727625
http://cgi.ebay.com/5-Amps-Voltage-Regulator-Module-Output-1-5-32V-LM338T-/130428364896

Eugenio
04-18-2011, 07:50 AM
Don't worry, the chip (http://www.national.com/mpf/LM/LM2596.html) has both overcurrent limitation and overheating cut off. A bit overkill, but you could get a 5A regulator if you feel the need:
http://cgi.ebay.com/LM338K-DC-AC-6V-30V-Out-DC-4-5V-28V-5A-Converter-/290547727625
http://cgi.ebay.com/5-Amps-Voltage-Regulator-Module-Output-1-5-32V-LM338T-/130428364896


The AC GH2 has an output of 1.2 mah. in my view the regulator has to have at most 1.5 mah for security reasons.

This thinking is wrong?

guyburns
04-18-2011, 09:23 AM
Eugenio: Your terminology is not correct. The AC adaptor for the GH2 is rated at 8.4 volts and 1.2 Amps (not 1.2 mah, which is milli-amp-hours). That means that if you draw a current of 1.2 Amps the output voltage will be a minimum of 8.4 volts (it could be slightly higher). Panasonic have decided that 1.2 Amps at 8.4 volts will power the GH2 under all conditions -- you do not need a regulator that can give more current as there is already a safety margin built in to the 1.2 Amp figure. Assuming the regulator you choose works to its specified ratings, a regulator rated at 1.2 Amps, or higher, will work correctly with the GH2. So you are correct in thinking that a 1.5 Amp regulator, "at most", will work okay.

If you are happy with the PTN78000WAH from Texas Instruments, go for it. It will work just as specified. Regarding the much cheaper units from Hong Kong, I don't know how they can manufacture them and post them so cheaply and still make a profit, given that the bulk price in the U.S. of the chip alone is more than the cost of the entire circuit board posted from HK (in lots of ten). Incredibly cheap. So cheap that I'm going to buy a couple just to play around with.

g.l
04-18-2011, 11:12 AM
The modified DCC8 that I am suggesting would of necessity (see below) have a regulator built in so that it outputs 7.2 volts.

But if you do that, there's no need to pretend to be an official battery, just allow a wide voltage input range so people can use cheap AC adapters > 11V.


I've been trying to think of a reason why Panasonic requires external supplies to be greater than 8.4 volts. The only one I have come up with is: for protection purposes.

There is no technical requirement at all, it's primarily so they can detect (and refuse to run) 3rd-party batteries. If the AC adapter (which doesn't have pins to ID itself as official) worked at the battery voltage, then 3rd party batteries would work too. So they have to use separate voltage ranges to allow AC adapters to work without the ID.

The clue is that the body turns on and runs, just to tell you that it refuses to run :). Of course the extra input tolerance is a nice side effect, but it's the first time I've ever seen it done. Most gadgets just die if you feed the wrong voltage in.

g.l
04-18-2011, 11:27 AM
Regarding the battery: I think you will be disappointed. You get what you pay for. I doubt very much that a 12 volt, 6.8Ah Li-ion battery costing $30 (with charger) will retain its capacity after more than a few discharges.

Same batteries I have. Not tested yet, but cheap Chinese stuff isn't necessarily bad. It won't be as good as a quality brand (and often the quality control sucks), but I still expect plenty of use from them. With Chinese stuff I recommend buying at least two, that way you have a spare at critical moments. Better two lower-mah, then one high-mah when it fails :).

As for the 12/9/5V version, don't assume that the outputs will be tightly regulated. I say that as my 12V version (which is also not a multiple of 3.6V) drops from 12.6V->10.8V.

Eugenio
04-18-2011, 01:24 PM
So you are correct in thinking that a 1.5 Amp regulator, "at most", will work okay.

Using a battery of 8.4 V with 4.500mah (4.5 A) without the voltage regulator can cause damage to GH2?

This statement is correct or camera will have any security mechanism that ensures the consumption of only 1.2 A?

tyampel
04-18-2011, 02:11 PM
Using a battery of 8.4 V with 4.500mah (4.5 A) without the voltage regulator can cause damage to GH2?

This statement is correct or camera will have any security mechanism that ensures the consumption of only 1.2 A?
The specifications say that that the camera consumes 3.6 W. For a 7.2V battery it comes down to 0.5A. Therefore 1 A or higher is plenty.
The 8.4 V battery cannot damage the camera no matter what its potential energy in Ah is. That number is just an indicattor how long the battery can last.
A 4500mAh battery will feed a camera consuming 500mA for 9 hours. The current flowing through the camera depends on its resistantance.
In the case of GH2 consuming 3.6 W from a 7.2V battery it is 14.4 Ohm. This is according to Ohm's law. I = V/R.

g.l
04-18-2011, 02:57 PM
The specifications say that that the camera consumes 3.6 W. For a 7.2V battery it comes down to 0.5A. Therefore 1 A or higher is plenty.

Note quite as simple. 3.6W is likely an average, however the camera way well require more ocassionally in small bursts (eg. when booting up). Otherwise the AC adapter would be a lower spec.


The 8.4 V battery cannot damage the camera no matter what its potential energy in Ah is. That number is just an indicattor how long the battery can last.Yep, as long as the voltage is correct, any device will only use as much current (amps) as it needs.

Eugenio
04-18-2011, 02:58 PM
Thanks tyampel.

A battery with these specifications:

DC input: 12.6V
DC output: 10.8V ~ DC12.5V
Rated current: 1000ma
Capacity: 6800mah

It would work perfectly with the voltage regulator PTN78000WAH?

Description of the voltage regulator PTN78000WAH:

1.5-A Output Current • General-Purpose, Industrial Controls,
• Wide-Input Voltage HVAC Systems, Test and Measurement,
(7 V to 29 V) VMeehdiicclaelsI,nMstarruinmee,natnadtioAnv,ioAnCi/cDsC Adaptors,
• Wide-Output Voltage Adjust
(–15 V to –3 V)
• High Efficiency (Up to 84%)
• Output Current Limit

Which left me in doubt was the "Rated current: 1000ma" of the battery in question.

tyampel
04-18-2011, 03:46 PM
Which left me in doubt was the "Rated current: 1000ma" of the battery in question.[/QUOTE]

It probably means that the battery can sustain a 1000mA load without negative side-effects (such as overheating) and damage.

Eugenio
04-18-2011, 03:52 PM
In my ignorance I thought that the voltage regulator needs an input voltage greater than 1.5 A.

I know one thing, in a week of reading I learned a lot about batteries and voltage regulators.

Yeah!

g.l
04-18-2011, 03:56 PM
Which left me in doubt was the "Rated current: 1000ma" of the battery in question.

Where did you see this?

As was said, it suggests that you shouldn't draw more than 1A from this battery, at least not continuously (the occasional burst may be OK, I'm not sure). But don't forget that 1A @ 12V is 1.43A @ 8.4V (so even with the 5-10% loss in the converter it should be OK).

g.l
04-18-2011, 03:57 PM
I know one thing, in a week of reading I learned a lot about batteries and voltage regulators. YeahI know what you mean, I'm trying to make sense of MOSFETs for a DIY intervalometer for 2 days now, and my head is spinning! If anybody knows these, PM me please.

Eugenio
04-18-2011, 04:01 PM
Postado Originalmente por Eugenio
O que me deixou em dúvida foi a "Corrente: 1000mA" da bateria em questão.
Onde você viu isso?


http://cgi.ebay.com/DC-12V-6800mAh-Super-Rechargeable-Lithium-ion-Battery-/150530536976?pt=US_Batteries&hash=item230c51b610

g.l
04-18-2011, 04:05 PM
http://cgi.ebay.com/DC-12V-6800mAh-Super-Rechargeable-Lithium-ion-Battery-/150530536976?pt=US_Batteries&hash=item230c51b610

They look almost identical to my batteries, but my seller didn't list a current limit, and the labels on mine or in the picture on your listing don't say anything about current limits. I've emailed my seller, I'll let you know what he says.

chon
04-18-2011, 11:09 PM
As for the 12/9/5V version, don't assume that the outputs will be tightly regulated. I say that as my 12V version (which is also not a multiple of 3.6V) drops from 12.6V->10.8V.
I didn't assume, I deducted. :-Dum(DBG):

3.6V is the nominal voltage of a Li-ion cell, but a full charged cell will likely have a higher potential, that's why they rate the 12V battery 10.8V (3x3.6V) to 12.6V.

5V and 9V are nowhere close to a multiple of the nominal range. Since the 5V and 9V output capacity (75 Wh and 76.5 Wh respectively) are close, but slightly lower than the 12V capacity (78 Wh), I deduct the 5V and 9V outputs are efficiently regulated.

That battery, if indeed regulated, is a great option, it's self contained, you'd only have to build the plug.

jo447
04-19-2011, 12:58 AM
I think this can do the trick :
http://cgi.ebay.com/ONE-9-VOLTS-DC-CCTV-Battery-Clip-Adaptor-2-1mm-tail-/270735064003?pt=LH_DefaultDomain_2&hash=item3f09113bc3

You just have to tape your 9v battery on the camera and you have a small and easy setup for the gh2
(not sure if it's 2.1mm output or 2.5 though...)

guyburns
04-19-2011, 06:00 AM
Keylight: In your first post you said:

I metered the adapter and it runs at 8.79v. When I connect the Adapter to the camera via my DIY DC adapter, the voltage drops to 8.70. The Amperage is 740mA…

Those figures for current and voltage are way above the specified value of ~3.5 Watts for power draw (8.7 x .74 = 6.4 Watts). Can you measure the current drawn from the adaptor (and the voltage) for three different scenarios (below)? I'd liked to know the current the GH2 actually draws:

1. Screen on default brightness, camera not doing anything.

2. Screen on default brightness, movie being recorded at 24/1080p.

3. Screen off, movie being recorded at 24/1080p.

And if you have an analogue current meter, can you measure the maximum current at switch on? An analogue meter is required (unless you have a peak-reading digital meter), because it has faster response and you can watch the pointer swing upwards.

g.l
04-19-2011, 06:20 AM
I didn't assume, I deducted. :-Dum(DBG):

You may be right - if you are, it's ideal. Question is:

- is the regulation tight?
- are there any protections (short-circuit, over current, temperature)? The better regulators like the TI have these.
- is 9V safe for the camera / is the 9V output maybe over 9?
- Can you draw from more than one output at the same time?

My instinct on the last one is 'yes, as long as you don't exceed the overall draw rating (whatever it is)'. However I did email an Ebay seller, and he said 'no, strictly one output only, or the battery gets overladed'. I said 'what if you stay inside the overall current rating?' but he insisted. My hunch is he didn't know what he was talking about, but I would double-check.

One final point, if you can build a regulator, then you can buy the cheaper batteries and save money in the long run.

g.l
04-19-2011, 06:24 AM
I think this can do the trick :
http://cgi.ebay.com/ONE-9-VOLTS-DC-CCTV-Battery-Clip-Adaptor-2-1mm-tail-/270735064003?pt=LH_DefaultDomain_2&hash=item3f09113bc3

It might work with NimH rechargables, as they hold their voltage fairly well until they run out. But normal batteries (alkalines etc) drop their voltage gradually - I don't know how much, but you may drop below the camera's voltage before the battery is really dead.

g.l
04-19-2011, 06:27 AM
They look almost identical to my batteries, but my seller didn't list a current limit, and the labels on mine or in the picture on your listing don't say anything about current limits. I've emailed my seller, I'll let you know what he says.

My seller claims 6000ma can be drawn from mine (12V 6800mah). Sounds right (problem is you can never trust people to get technical things right).

Eugenio
04-19-2011, 08:10 AM
My seller claims 6000ma can be drawn from mine (12V 6800mah). Sounds right (problem is you can never trust people to get technical things right).


Could you please post the link of the seller you buy?
I never bought on ebay, I need a good indication someone that send to Brazil.

Eugenio
04-19-2011, 12:25 PM
I ordered my PTN78000WAH voltage regulator, it will arrive within 15 days.

I'm thinking of attaching an LED illuminator in the same battery (12v 6800mah) that will make the power of GH2.

I can connect the illuminator directly from the battery without going through the voltage regulator?

This can compromise the quality of energy sent to the GH2 through the voltage regulator?

Technical Specification of LED Illuminator:

Type power cord (6V-17V DC)
Maximum power consumption: Approximately 10W

This is the LED illuminator:

http://lacoloronline.com/product/?CM900-Comer-CM-LBPS900-LED-Light-

guyburns
04-19-2011, 10:27 PM
I ordered my PTN78000WAH voltage regulator, it will arrive within 15 days.

I'm thinking of attaching an LED illuminator in the same battery (12v 6800mah) that will make the power of GH2.

I can connect the illuminator directly from the battery without going through the voltage regulator?

This can compromise the quality of energy sent to the GH2 through the voltage regulator?

1. Connecting the LED light to the battery is fine. Power to the GH2 through the regulator will be okay.

Now let's do some calculations of power:

GH2 … 6.4 Watts (as measured by Keylight, see http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2314614&viewfull=1#post2314614)
Inverter losses (assumed 85% efficient) … 1.0 Watt
LED … 10 Watts

Total = 17.4 Watts.

Battery capacity = 12 x 6.8 = 82 Watt-hrs
Run time = 82/17.4 = 4.7 hours

Throw in another factor of 10% just for the sake of it, and run time = 4.2 hrs. And with a no-name battery, I would expect another 20% drop within a few dozen discharges, to give an estimated, real-life runtime of about ~3 hrs after a bit of use.

Eugenio
04-19-2011, 11:12 PM
1. Connecting the LED light to the battery is fine. Power to the GH2 through the regulator will be okay.

Now let's do some calculations of power:

GH2 … 6.4 Watts (as measured by Keylight, see http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2314614&viewfull=1#post2314614)
Inverter losses (assumed 85% efficient) … 1.0 Watt
LED … 10 Watts

Total = 17.4 Watts.

Battery capacity = 12 x 6.8 = 82 Watt-hrs
Run time = 82/17.4 = 4.7 hours

Throw in another factor of 10% just for the sake of it, and run time = 4.2 hrs. And with a no-name battery, I would expect another 20% drop within a few dozen discharges, to give an estimated, real-life runtime of about ~3 hrs after a bit of use.

Better to use the LED with a separate battery, it uses Sony batteries, I'll buy two NP-770.

My PTN78000WAH regulator is on the way, I gave it a read the manual and I was scared with the amount of information.

I will seek a professional with enough experience, do not want anything goes wrong.

It is very complex to configure PTN78000WAH to work with a 12V input and output of 8.6 v? Even for those who have a good grasp of electronics?

guyburns
04-20-2011, 12:43 AM
No, it should not be complex for someone who knows what they are doing, and tests the unit after construction. The circuit diagram is on page 1 of the PDF. Only three additional components are required. I don't know where you will mount them.

C1
A 2.2 microfarad , 25 volt, multilayer ceramic capacitor, as described on page 13 and Table 5 on page 15. It's a surface mount device (a pain to use) and cost about 20 cents. This is a tricky component to get hold of. I've never had to use one and hobbyist shops probably don't sell it. Here is what C1 will look like: http://australia.rs-online.com/web/compChooser/compChooserAction.html?method=retrieveTfg&Nr=AND%28avl%3aau%2ccomponentChooser_au%3aY%2csear chDiscon_au%3aN%29&N=4294569320%204294635860+4294635735&No=0

C2
A 100 microfarad, 16 volts electrolytic capacitor. Commonly available.

R(set)
A 1%, 1/2 or 1/4 Watt resistor whose value can be calculated from formula (1) on page 10. I worked it out as 4.3 kohms. Luckily this a standard value in the 1% range. You can calculate the output voltage from this formula, but rearrrange (1) yourself to make sure this is correct:

V = (82.1 + 2.5R)/(6.49 + R) = 8.61

Instead of cluttering up this thread with electronic questions, gmail me at gdburns. I'd like to know how you get on.

Eugenio
04-20-2011, 08:32 AM
So my mission now is to find these components to configure the voltage regulator to an output of 8.6 v / 1.5 A. - Knowing that the input is 12V

I ask for help with parts list and if possible a link to where I can buy them.

I'll send you an email guyburns, I'm counting on your help.


I think the list of required components should be part of this topic, it will be useful to others interested in the configuration of voltage regulator PTN78000WAH.

Svart
04-20-2011, 09:15 AM
wow, you guys are making things much harder than they need to be.

12v 2A wall wart.
LM317 adjustable regulator
a couple caps, a couple resistors and a pot.

Voila, an adjustable 1.5A regulator where you can dial in your own voltage.

http://www.national.com/mpf/LM/LM317.html#Overview

Eugenio
04-20-2011, 11:33 AM
wow, you guys are making things much harder than they need to be.

12v 2A wall wart.
LM317 adjustable regulator
a couple caps, a couple resistors and a pot.

Voila, an adjustable 1.5A regulator where you can dial in your own voltage.

http://www.national.com/mpf/LM/LM317.html#Overview


This option works the same way that PTN78000WAH?

Can I put any type of 12v battery and with over 6000mAh?


This alternative is as functional and safe as PTN78000WAH?

I really liked the arquiterura PTN78000WAH, his size is pretty nice

Svart
04-20-2011, 12:03 PM
no, what I suggested is a .50$ adjustable linear regulator. It is not a switching regulator.

You won't have to filter excessively to get rid of the hash that the switching regulator that you want to use will have on it's outputs.

The LM317 is 10mm x 16mm so it's smaller than your PTN78000WAH which is 13mm x 19mm.

What I'm trying to say is that there is just no good reason to use a 20$ switcher where a .50$ linear will do.

Eugenio
04-20-2011, 12:25 PM
So I could have saved a lot in this adaptation, now it's late, the PTN78000WAH cost me almost $ 60 with shipping and taxes included. = (

I have read and have the manual, but if someone could list here in this thread the name of the parts with the correct references for setting the regulator to enter 12v and hang out with v 8.6, will be of great value.

Help

Svart
04-20-2011, 12:33 PM
The diagram on the page I linked you to is the generic adjustable setup for this regulator. Just build it and adjust the output with the camera attached.

So I worked the formula real quick:

The closest you can get with standard resistors is 8.7V with R2=1K43 and R1=240R. With a multi-turn potentiometer you can get closer under load.

Eugenio
04-20-2011, 12:50 PM
So I will not need the PTN78000WAH to make the reduction from 12 v to 8.6 v? I need only the part that you mentioned?

Or this part will work in conjunction with the PTN78000WAH?

Svart
04-20-2011, 12:56 PM
the LM317T is a voltage regulator. It will output 8.7Vdc when fed 12vdc after being configured properly. You don't need the PTN78000 part when using it.

Eugenio
04-20-2011, 01:09 PM
I already bought PTN78000WAH and have to give him useful.

Who will arm the system is a professional, I just want to facilitate his work, purchasing all equipment necessary to attach to PTN78000WAH

The next project I will use the LM317T, I plan to buy my second GH2.

Thanks Svart, We thank you more if you can list in detail the parts for PTN78000WAH

guyburns
04-20-2011, 11:51 PM
wow, you guys are making things much harder than they need to be.

Eugenio is, not me. I did warn him about trying to make electronic devices at home: http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2313358&viewfull=1#post2313358



What I'm trying to say is that there is just no good reason to use a 20$ switcher where a .50$ linear will do.

Yes there is: a switcher loses less power and does not require a heatsink. To power the GH2 externally you need a supply of >8.4 volts rated at 1.2 Amps that typically puts out 740 mA (this measured current figure comes from the first post in this thread and I assume it is correct). Let's design a regulator to provide 8.6 volts at a current of 800 mA, driven by a certain number of Panasonic, Li-ion, 3.7 volt, 1950 mAh batteries. (http://www.panasonic.com/industrial/includes/pdf/Panasonic_LiIon_CGA103450A.pdf).

LM317 design
Minimum input/output differential: 2.5 volts. Let's say 3.0 volts.
Thermal resistance (junction to case): 65ºC/Watt.

For this design to regulate properly, it requires a minimum input voltage of 8.6 + 3.0 = 11.6 volts (3.9 volts/cell). Would a three-cell Li-ion pack work? Not really. The "Discharge Graph" of the PDF for this battery (see above), at an interpolated 800 mA, indicates it would provide only about 400 mAh down to 3.9 volts, below which the output voltage of the regulator would start to fall. So we'd only get 400 mAh from these cells. Not good.

Let's try 4 cells. That gives us a starting voltage of 16.4 volts, and a cut-off point of 2.9 volts (11.6/4) before the regulator output begins to fall. That's good. It means the batteries provides all their capacity. Are there any problems with this design? Yes – power dissipation!

Power dissipated in LM317 for fully charged batteries = (16.4 - 8.6) x 0.8 = 6.2 Watts. It can be shown (too complicated to explain here) that the LM317 has a maximum power dissipation, without a heatsink, of about 1.5 Watts. We need a heatsink on the LM317 when run from fully charged batteries. My calculations show that the heatsink would have to be rated at less than 15ºC/W, i.e. something like this: http://www.jaycar.com.au/productView.asp?ID=HH8504

An LM317 design sounds simple, but really, it is not in the running. You need an LM317, a resistor, a pot, 2 capacitors, a heatsink, a circuit board, a mounting case, and input and output sockets. About $10 dollars of components, and 5-6 hours to build. But worst of all, is the power wasted in the LM317 over the complete discharge cycle of the Li-ion batteries – on average 4.5 Watts (800 mA at an average volta drop across the LM317 of 5.6 volts). In providing about 6 Watts to the GH2, you need 10 Watts from the battery. 40% of the battery capacity is wasted.

There are switcher equivalents of the LM317 (http://products.cui.com/adtemplate_child.asp?brand=v-infinity&p=326824&c=972438&catky=328060&subcatky1=521999&subcatky2=568080#), and they would not need a heatsink, and would have minimal power loss. To me, the ideal external power for a GH2 would be to have a switcher LM317 set to 7.2 volts, housed inside a DCC8.



The next project I will use the LM317T, I plan to buy my second GH2.

The LM317 may not be a good idea.. There are better, off-the-shelf solutions.

SUMMARY
It is not easy to get the best out of an external power supply when trying to assemble the components yourself. And by best I mean it has to be reliable, look aesthetic, and uses all of the battery capacity available. Do you choose Li-ion, NiMH or Lead acid? What capacity? What voltage? How are you going to charge it? How are you going to connect it? You could end up with a hotch potch of components and leads that look a mess and which only uses 25% of the battery capacity. Check out my Batteries in the Wild (http://www.candlepowerforums.com/vb/showthread.php?313384-Battery-power-in-the-wild-%96-suggestions-wanted&p=3626223&viewfull=1#post3626223) post for more discussion about external power for the GH2 and other devices.

And for those interested in batteries: the best single document I have come across is: http://www.national.com/appinfo/power/files/f19.pdf.

g.l
04-21-2011, 04:12 AM
As guyburns is showing, it's not trivial to build electronics devices. The devil is in the details (hell, I just spent two days reading MOSFET datasheets).

guyburns, maybe you should build and sell voltage good regulators here, might be some money in it (nobody ask me, I'm too busy as it is :)).

Svart
04-21-2011, 08:00 AM
Heh. I design switching power supplies for a living. I can tell you guys about some stuff that's not trivial.

This is trivial. :)

I know what you are saying Guyburns, you seem like a very knowledgeable person and are certainly on the right track with your ideas. If this were some production design, I would agree 100% about the use of a SMPS for this. However, this is just a quick and cheap project for most and cash is king.

I personally have to make choices every day about what I'm going to use to power devices with these things. Sometimes I use switchers, sometimes I use linears(of various types). It all depends on quality of the output, cost, ease of use, and waste.

Something like this doesn't need to be extremely efficient, but it DOES need to be quiet (no hash, no ground bounce, no transients, etc), a linear excels here. Maybe not even a LM317T, maybe a linear pass element would work better as you can scale your darlington to meet dissipation requirements.

In any case, I don't understand where you are coming from with the battery/LM317T discussion. I thought this was simply a wallwart to camera adapter discussion? In either case, you are doing math for increasing the voltage to 16.4V, which I do not understand. I would PARALLEL the cells up and get more current and leave the voltage the same. Anyway, you just can't do that with LI-ION as the battery watchdogs are usually only designed to monitor 2-3 series and 2-3 parallel cells. In this case, any battery I want to upgrade, I would choose higher mAh for each cell.


An LM317 design sounds simple, but really, it is not in the running. You need an LM317, a resistor, a pot, 2 capacitors, a heatsink, a circuit board, a mounting case, and input and output sockets. About $10 dollars of components, and 5-6 hours to build.nah it's more like 2$ in parts(that you buy), (not sure where you get your parts) and you could do away with the pot if you used the resistor values I mentioned earlier and save more money. I'd just thermal glue to the LM317 to an old computer CPU heatsink and use the 12v input to power the fan too. But I'd also do this because I have all this laying around my lab and can build it for free.

Besides, for the switching design, you also need (minimum) 2 caps (probably expensive low ESR tantalums for output stability of the switcher), 1 resistor (for output V setting) and the same case/mounting you would need for the linear supply for a net difference between the designs of 1 resistor but possibly add a couple more $$ for the caps. So you really aren't gaining anything much, just lower dissipation(at the cost of needing more filtering or gaining more noise).

Eugenio
04-21-2011, 08:32 AM
I need to know the names of parts that will be part of the voltage regulator PTN78000WAH.

I'm going to use 12v battery with 6800mah and I want the regulator to convert 8.6 v 1.5 A

Please someone help me.

guyburns
04-21-2011, 08:57 AM
As guyburns is showing, it's not trivial to build electronics devices. The devil is in the details (hell, I just spent two days reading MOSFET datasheets).

guyburns, maybe you should build and sell voltage good regulators here, might be some money in it (nobody ask me, I'm too busy as it is :)).

Don't reckon there'd be any money in it, except if the Chinese took it on. I don't know why they haven't. The made a battery for the GH2, and they should be churning out DCC8s and 8.6 volt regulators. What I will be doing in the next few weeks is buying one of those $5 converters from HK, running it for a week or two at maximum output, and testing it thoroughly.

Eugenio
04-21-2011, 09:32 AM
"I need to know the names of parts that will be part of the voltage regulator PTN78000WAH."

The text below is a list of parts that I need?



C1
Um microfarad 2.2, 25 volts, capacitor cerâmico multicamadas, conforme descrito na página 13 e Tabela 5 da página 15. É um dispositivo de montagem em superfície (uma dor de utilização) e custou cerca de 20 centavos. Este é um componente complicado pegar. Eu nunca tive de usar e amadores balcões provavelmente não vendê-lo. Aqui está o C1 será parecido com: http://australia.rs-online.com/web/c...294635735&No=0

C2
Um microfarad 100, 16 volts capacitor eletrolítico. Comumente disponíveis.

R (conjunto)

A 1%, 1 / 2 ou 1 / 4 watt resistor cujo valor pode ser calculado a partir da fórmula (1) na página 10. Eu trabalhei para fora de 4,3 kohms. Felizmente, este valor padrão na faixa de 1%. Você pode calcular a tensão de saída a partir desta fórmula, mas rearrrange (1) se a certeza de que essa é correta:

V = (82,1 + 2,5 R) / (6,49 + R) = 8,61


If anyone knows any site where to find these parts, and the quantity of each part, tell me !!!

g.l
04-21-2011, 10:34 AM
Heh. I design switching power supplies for a living. I can tell you guys about some stuff that's not trivial. This is trivial. :)

Sure, for someone with your experience. Not for the hobbiests and non-pro hackers that tend to hang out here.


I know what you are saying Guyburns, you seem like a very knowledgeable person and are certainly on the right track with your ideas. If this were some production design, I would agree 100% about the use of a SMPS for this. However, this is just a quick and cheap project for most and cash is king.The TI part can be gotten as a free sample from the TI website, or the 3A version is on Ebay (http://cgi.ebay.com/Step-Down-Switching-Regulator-Module-45W-2-5-12-6V-out-/180642927593?pt=LH_DefaultDomain_0&hash=item2a0f2853e9) for a decent price. It also has all kinds of protections that are useful (including overheating), especially for people not super-schooled in making their own circuits, thermal management etc. and therefore liable to make mistakes which could (at worst) kill their camera - and it's efficient, saving money on wasted battery juice. And it also just needs two caps and one resistor (better quality ones, sure), but not even a heatsink. Worth the extra money considering (as you point out) you need parts and an enclosure either way.

And then you can use cheap AC and your own batteries (people care because the official ones are small and bloody expensive). So as you get both options from the one part, to me it's worth the investment, even if you buy the part.

Svart
04-21-2011, 11:13 AM
if you can get that module for 10$ then, it's considerably more viable than the 20$ I saw it for on mouser's site. Good find!


And then you can use cheap AC and your own batteries (people care because the official ones are small and bloody expensive). So as you get both options from the one part, to me it's worth the investment, even if you buy the part.

You'd still need some way of stepping down line level and then rectifying so you can't get around using a wall wart or switcher of some kind.

If it were me, I'd just get a 12V 2A smps and adjust the feedback divider around the tl431(what most use for voltage monitoring on the outputs) until you get ~8.6v. I've done this before for one-off projects that need odd voltages.

What I'd really like to know is what IC panny is using to control the battery. That way we'd really know what we can safely feed the camera with. Chances are that 9vdc is perfectly fine and that all this talk about getting exactly 8.6V is really just academic but not realistic.

g.l
04-21-2011, 12:00 PM
You'd still need some way of stepping down line level and then rectifying so you can't get around using a wall wart or switcher of some kind.

I would use generic 12V 1A switchers like these (http://shop.ebay.co.uk/i.html?_nkw=12+1A+power&_sacat=0&_sop=15&LH_PrefLoc=2&_odkw=12+1A&_osacat=0&_trksid=p3286.c0.m270.l1313) (ultra cheap and easy to replace if it ever dies).


What I'd really like to know is what IC panny is using to control the battery. That way we'd really know what we can safely feed the camera with. Chances are that 9vdc is perfectly fine and that all this talk about getting exactly 8.6V is really just academic but not realistic.

Agreed - the circuit boards can be seen here (http://www.gh1-hack.info/wiki/GH2EncryptionAndDumpingInformation), see if you can spot the part.

Eugenio
04-21-2011, 12:08 PM
I'll buy the components for PTN78000WAH in the site of Texas Instruments. Please someone post it here for me the link for each component that must surely have in stock of Texas Instruments

http://www.ti.com/

Svart
04-21-2011, 12:19 PM
So on another note, I got my chinese batteries the other day. I've opened one up and found two flat/rectangular cells in series and a small PCB with mosfet, controller IC and supporting parts. I have not tried these batteries yet as my camera is on loan to a director I'm working with right now.

Good news:
The PCB and parts are seeming good quality. The PCB is actually silkscreened and in english. It seems to be of higher quality than a lot of production chinese batteries I've come across.

Bad news:
The cells are unbranded and unidentifiable. I have not found anything similar at all from any of my sources.
The controller IC is also completely unmarked.


Neutral news:
The data(D) pin leads to the IC. Not sure if any communication happens or not. When I get the camera back I'll hook it up to the scope and see.
The thermistor(T) pin leads to a voltage divider and some sot23 mosfets. Not what I expected. Usually there is either a thermistor or a dummy load connected here as most battery controllers need to see some load here to turn on.

guyburns
04-22-2011, 04:21 AM
Q1: Can you take a close up of battery internals and both sides of the PCB, and gmail them to gdburns? Jpeg >2 MB if possible.

Q2: Where did you buy this battery?

Q3: Does it look like it would be possible to remove the batteries, keep the existing PCB, and leave enough room for another PCB? What would be the maximum size of an additional PCB?

guyburns
04-22-2011, 04:56 AM
For reference: this thread http://www.dvxuser.com/V6/showthread.php?246528-alternative-to-the-dmw-ac8 states that a particular AC-DC adaptor, 9.5 volts, 2A, works acceptably into the DCC8 to power the GH2.

Svart
04-22-2011, 08:27 AM
Q1: Can you take a close up of battery internals and both sides of the PCB, and gmail them to gdburns? Jpeg >2 MB if possible.

Q2: Where did you buy this battery?

Q3: Does it look like it would be possible to remove the batteries, keep the existing PCB, and leave enough room for another PCB? What would be the maximum size of an additional PCB?

I'll get some pics today, however the soldermask is white and you cannot see the traces at all. Tracing through with a meter shows that the PCB is mostly just an over/under voltage protection circuit. There is a single mosfet that makes/breaks the - side of the battery.

I got it on ebay. I'll link to it later. I wanted to hold off linking to it in case it was a poorly designed battery so that folks won't buy junk. So far it seems decent enough though.

Yes, after removing the batteries(99% of the whole volume of the pack) there is plenty of room for other things.

tyampel
04-22-2011, 09:46 AM
For reference: this thread http://www.dvxuser.com/V6/showthread.php?246528-alternative-to-the-dmw-ac8 states that a particular AC-DC adaptor, 9.5 volts, 2A, works acceptably into the DCC8 to power the GH2.

I am using it too. Works fine and the connector is a perfect fit.

guyburns
04-22-2011, 11:14 AM
I am using it too. Works fine and the connector is a perfect fit.

Could you (or someone else using a similar external supply) measure the open-circuit voltage of the power supply and the current drawn from the supply by the GH2? I want to confirm that 9.5 volts is not too-high a voltage, and that the GH2 draws about 800 mA when powered externally (according to post 1).

tyampel
04-22-2011, 01:51 PM
Could you (or someone else using a similar external supply) measure the open-circuit voltage of the power supply and the current drawn from the supply by the GH2? I want to confirm that 9.5 volts is not too-high a voltage, and that the GH2 draws about 800 mA when powered externally (according to post 1).
The adapter outputs 9.61V when open.
I also measured the voltage coming ffrom 8 NiMH (Eneloop) cells. It comes to 10.46V open.
When connected to GH2 body (no lens) the voltage drops to 10.08V. With the 14-140 lens attached the voltage drops to 9.8V. The camera seems to be fine with it for over 10 minutes.

So it seems even 10V is safe. I tried to connect a DC adapter rated at 9V that displayed 12.5V when open and the camera did not even turn on.

Unfortunately my current meter is maxing out at 200mA so I cannot measure the current going through.

guyburns
04-22-2011, 08:34 PM
So it seems even 10V is safe. I tried to connect a DC adapter rated at 9V that displayed 12.5V when open and the camera did not even turn on.

Thanks for the testing, Tyampel.

In general, if the open-circuit voltage of an adaptor is more than about 0.1 volt higher than the rated voltage, that's a clear sign of poor, or no, regulation. Such a supply probably won't be able to jump the 8.4-volt cut-off hurdle of the GH2.

I think it is safe to say that a regulated supply up to 10 volts will drive the GH2 without damaging it. But a lower voltage may mean less current (unless the GH2 is a constant power device), that's why a lower-voltage supply may be better – but not too low. It has to stay away from the 8.4 cut-off.

I would not suggest anyone try higher than 10 volts, especially not unregulated, as there will come a point when your GH2 goes "poooof".

As it stands, Keylight's 780 mA measurement indicates the GH2 is drawing almost twice the power from an external source as from the internal battery. The figure should be confirmed to allow for accurate calculation of run times.


Unfortunately my current meter is maxing out at 200mA so I cannot measure the current going through.
Even the cheapest digital multimeters (well, at least the cheapest I've seen: http://cgi.ebay.com.au/LCD-Digital-Multimeter-Voltmeter-Ohm-Volt-DMM-Tester-/330506361135?pt=AU_B_I_Electrical_Test_Equipment&hash=item4cf3b6d92f#ht_3391wt_1141), come with a 10 Amp DC input socket which will be separate from the 200 mA socket. Are you sure your meter doesn't have a 10A socket?

mslade
04-22-2011, 09:16 PM
So after epic fail with a radio shack 9v 1200mAh supply I got the HQRP supply from Amazon today. Fired the cam right up with my homemade adapter. Marked as 9.5 v 2A but is putting out 9.74v.

Also found an external battery at RS. It works perfect with the adapter, but I don't have a run time yet. Charging it overnight and will test tomorrow to see how long it will last. $32 ain't bad if it will last a while.
33280
Mark

mslade
04-23-2011, 11:17 AM
Well that RS battery didn't work. New from the store it was 9.23v and it fired up the cam.....but after charging, it was 11.24v and the cam wouldn't turn on. RS has a similar 7.5v battery. I wonder if that will be a higher voltage when charged and work. Might try one when I return this one....

Mark

keylight
04-23-2011, 12:55 PM
Well that RS battery didn't work. New from the store it was 9.23v and it fired up the cam.....but after charging, it was 11.24v and the cam wouldn't turn on. RS has a similar 7.5v battery. I wonder if that will be a higher voltage when charged and work. Might try one when I return this one....

Mark

Mark,

I'd suggest trying a hobby store if there's one near you. The 8.4v RC car battery has worked flawlessly for me now for a couple of weeks. Seems to me (and I'm not an expert on this stuff, others posting here definitely have more knowledge) that a lower voltage higher amperage battery is a much better solution. Even if that RS battery did work, it was only 1200mAh - it would not have lasted all that long. A battery with a much higher amperage is going to last you a lot longer, and should put out a voltage that doesn't deviate as far from it's rating. A slow decrease in voltage over a long period of time is probably a better approach.... Hopefully others will correct me if I'm wrong on this.

mslade
04-23-2011, 02:00 PM
I'm sure you are right. I saw it was 9.5 at 1600 and figured it was worth a shot for $32.

Mark

tyampel
04-23-2011, 07:50 PM
I'm sure you are right. I saw it was 9.5 at 1600 and figured it was worth a shot for $32.

Mark

You are better off with a pack of 8 NiMH batteries. I use the Eneloop ones as they tend to keep their charge when not used. These are rated at 2000mAH.
Amazon is a good source of them. You will need two battery holders from Radio Shack along with some Adaptaplug accessories. The right connector is "C" .

Good luck.

cordvision
04-29-2011, 12:49 AM
Mark,

I'd suggest trying a hobby store if there's one near you. The 8.4v RC car battery has worked flawlessly for me now for a couple of weeks.
I also have one of these 8.4v RC car batteries. It powers the camera without any problem (homemade battery adapter), but I'm just worried to run it for a longer time because the voltage of the battery when fully charged is over 10 Volts. Does anybody know of anyone who damaged their camera with an 8.4V RC car battery?

keylight
04-29-2011, 01:07 AM
I also have one of these 8.4v RC car batteries. It powers the camera without any problem (homemade battery adapter), but I'm just worried to run it for a longer time because the voltage of the battery when fully charged is over 10 Volts. Does anybody know of anyone who damaged their camera with an 8.4V RC car battery?

I documented my battery running for just over 8 hours (first post in this thread). I wouldn't be concerned.

BTW, are you metering it at 10v with load from the camera, or without any load?

tyampel
04-29-2011, 09:07 AM
[
Even the cheapest digital multimeters (well, at least the cheapest I've seen: http://cgi.ebay.com.au/LCD-Digital-Multimeter-Voltmeter-Ohm-Volt-DMM-Tester-/330506361135?pt=AU_B_I_Electrical_Test_Equipment&hash=item4cf3b6d92f#ht_3391wt_1141), come with a 10 Amp DC input socket which will be separate from the 200 mA socket. Are you sure your meter doesn't have a 10A socket?[/QUOTE]

Mine is a 20+ years old RadioShack model. But you are right. These multimeters are very cheap these days. I ordered a better one from China for under $10 including shipping.

guyburns
05-02-2011, 04:09 AM
My imitation GH2 battery has arrived and these are my test results for capacity. Battery rated at 1200 mAh. Capacity determined by discharging at 400 mA until the voltage reached 6.6 volts. Charging was by two methods (as a check on each other):


(1) Using a dedicated charger which began its charging at about 500mA, gradually dropping as the voltage increased, then switching to a constant-voltage charge (8.30 volts) until the current decreased below about 5 mA.

(2) Constant current of 400 mA until 8.40 volts, then constant current at 60 mA (the voltage dropped at this point), terminating when the voltage again reached 8.40.

The two charging regimes were slightly different, but I didn't expect to see any difference in capacity – and I didn't. Both methods resulted in a fully charged battery.

Results (mAh)
830, 840, 780, 870, 840, 840, 840.

The battery, ~$15 from elect_stores, has about 2/3 of the rating of the official Panasonic battery (yet to be tested). I don't imagine that any other 3rd-party battery would have superior specs at that price point, though I may be wrong.

Still to come: pulling the battery apart to find out what is inside.

3rd-Party DCC8
I have contacted every eBay seller of GH2 batteries suggesting they ask their supplier to manufacture a DCC8 with inbuilt switching regulator ("same as battery, but with no battery, just electronics"). I provided suitable links so they knew what I was talking about. Only one replied, Jimmy from electronic_sell:


Thanks for the information about that item. I have reported it to the factory, if there's any further message, I'll contact me you.

Best Regards
Jimmy

If anyone sees a 3rd-party DCC8 come up for sale on eBay, please post here.

badpix
05-04-2011, 08:59 AM
I'll post my notes related to the GH2 battery external power source.
Inspired by the home made dc battery adapters, I decided to make my own out of a block of plexiglas.
After duplicating the battery shape, I drilled two holes straight down for the supply terminals. I bored a slightly larger hole act as a retainer to hold a drop of solder I placed on the end of the wire.
At the bottom opposite the body wire access port I drilled a hole large enough to accomodate both wires and a piece of shrink wrap tubing.
I fed the wires though my holes, snugged up the solder at the top and filed the drops flat. The shrink wrap held the wires in place.

Power Supply
From MicroCenter, I purchased a Velleman "Compact Switching Mode Universal DC power adpater", $49.99
Input: 110 to 240 volts
5 to 24 volt output in 1 volt steps, 4.3 to 1.3 A

I first tried it with 7 volts. Camera responded "Battery not recognized" (or something like that)
Then 8 volts.... camera gave same response.. not recognized
Then 9 volts.... Camera repsonded normally

I shot continuously for 1 hour and 45 minutes using a 30 second exposure with 10 second intervals.

Everything seems to be working fine. Camera was warm, but not as hot as during extended video shooting.

Voltage during shooting remained a constant 9.15 volts
Current at idle (between exposures) 390 ma
Current during 30 second exposure 350 ma
Current during write to SD jumped momentarily to around 410 ma

At the moment, I'll use my APS 110 volt office backup as a power source. I suspect there are some good 12 volt to 9 volt DC converters out there which might be a better solution

Here's what my plexi adapter looks like:
Try this link.. https://files.me.com/badpix/8pwezw

guyburns
05-05-2011, 04:31 AM
Thanks for detailing you findings, especially the current figures – they confirm Pansonics quoted power consumption of ~3.5 Watts (from the battery). This implies that most of the circuitry of the GH2 probably works under constant power.

If Keylight is reading this, maybe you could edit your first post to include these figures (your figure of 790mA is probably incorrect). I will also edit my posts where I included the higher power figure.

keylight
05-05-2011, 08:47 AM
Thanks for detailing you findings, especially the current figures – they confirm Pansonics quoted power consumption of ~3.5 Watts (from the battery). This implies that most of the circuitry of the GH2 probably works under constant power.

If Keylight is reading this, maybe you could edit your first post to include these figures (your figure of 790mA is probably incorrect). I will also edit my posts where I included the higher power figure.

Yes, definitely. I've updated first post to include:



Voltage during shooting remained a constant 9.15 volts
Current at idle (between exposures) 390 ma
Current during 30 second exposure 350 ma
Current during write to SD jumped momentarily to around 410 ma


If there are other updates you think would be helpful, let me know. And if you want to write those changes up, I can just quote it into the first post. That would be incredibly helpful.

guyburns
05-05-2011, 11:25 PM
In case this info isn't already in this thread:


The RadioShack Adaptaplug type "C" is good fit for the DMW-DCC8.
But a better solution is to buy a Sony power adapter for their portable DVD players rated at 9.5 V. The plug fits perfectly and voltage is appropriate as well.

(from Tyampel in this thread: http://www.dvxuser.com/V6/showthread.php?248127-DMW-DCC8-socket)

And from Brunerww in the same thread:


The plug is 1.7mm inner diameter (ID) and 4.75mm outer diameter (OD) like this one (http://www.amazon.com/Right-Angle-Power-Plug-Cable/dp/B004GIGUZG?tag=battleforthew-20) from Amazon. Sadly, it is out of stock, but I also found it here (http://www.altex.com/Right-Angle-DC-Power-Plug-w-6-Cable-17mm-ID-475mm-OD-TC275-P147391.aspx).

guyburns
05-05-2011, 11:34 PM
If there are other updates you think would be helpful, let me know. And if you want to write those changes up, I can just quote it into the first post. That would be incredibly helpful.

These threads get unwieldy after a while and need to be summarised when the majority of info is in. In several months time I'll start a new thread (with a link to this one) with a title such as: [I]GH2 DC Power Characteristics /I].

adolgin
05-06-2011, 05:47 AM
Thanks for detailing you findings, especially the current figures – they confirm Pansonics quoted power consumption of ~3.5 Watts (from the battery). This implies that most of the circuitry of the GH2 probably works under constant power.

If Keylight is reading this, maybe you could edit your first post to include these figures (your figure of 790mA is probably incorrect). I will also edit my posts where I included the higher power figure.
Guyburns, while working on our adapter recently, I looked at the current consumption with a scope (which is much faster than a voltmeter in case not everyone is familiar). The camera indeed draws up to ~.8A in some situations for approx. .5 - .8 sec. I saw it on turn on, and also immediately after using it's own flash. While it does not affect average power consumption, a weak AC power adapter or weak battery would drop their output voltage for that short time and cause the camera to turn off showing the battery message. HTH

guyburns
05-10-2011, 04:08 AM
The camera indeed draws up to ~.8A in some situations for approx. .5 - .8 sec. I saw it on turn on, and also immediately after using it's own flash. While it does not affect average power consumption, a weak AC power adapter or weak battery would drop their output voltage for that short time and cause the camera to turn off showing the battery message. HTH

That's interesting, a lower inrush current than I was expecting. Since the figure is less than about 1 Amp, that would allow the use of this device: http://products.cui.com/adtemplate_child.asp?brand=v-infinity&p=46094&c=194683&catky=&subcatky1=&subcatky2=, a small switching regulator that is a pin-for-pin replacement for the common MC7800 line of linear regulators.

jo447
05-17-2011, 12:12 AM
I took the time to take a picture of my power setup for the gh2 rig

34205

I use the V-mount plate from TILTA with 5v output for the H4n, 9.3v for the GH2, 12v for my led light
and I still have 2 d-tap output (1 will be used for a monitor)

So far it works, and I'm quite happy.
more than 3hours of camera, light and sound with only 1 battery :-)

Thanks for the forum for the 9.3v value (I guess 8.6v would work as well, and that's probably the value I would choose if I had to order a new plate again, as it's closer to 8.4v)

B3Guy
05-18-2011, 09:13 PM
Hey, guys! I'm new here on the forum, and I just got a brand new GH2. I'm thinking that for the type of shooting I will be doing, powering off of Tamiya connector R/C batteries would be ideal from a size and weight standpoint. (also, I already have a charger.) What is the recommended setup for this? 8.4v battery, DCC8? What about adding something like this to make battery level monitoring possible?

http://www.alphasportrc.com/index.php?main_page=product_info&cPath=2_27&products_id=1468&language=en

keylight
05-18-2011, 11:50 PM
I use an 8.4v like you see in the very first post. Timed out at 8 hours. It's small enough to fit in my pocket and give me a whole day of shooting. You'll need a DCC8 or you can make your own of course. That meter looks interesting. I'd probably spend the money on a second battery though.... Good luck. Hope you'll post what you end up making...

B3Guy
05-18-2011, 11:57 PM
oh for sure I will share!

tyampel
05-19-2011, 07:33 AM
Hey, guys! I'm new here on the forum, and I just got a brand new GH2. I'm thinking that for the type of shooting I will be doing, powering off of Tamiya connector R/C batteries would be ideal from a size and weight standpoint. (also, I already have a charger.) What is the recommended setup for this? 8.4v battery, DCC8? What about adding something like this to make battery level monitoring possible?

http://www.alphasportrc.com/index.php?main_page=product_info&cPath=2_27&products_id=1468&language=en
8.4 is borderline in my opinion. If voltage drops to 8.37V you will get the mesages that the battery cannot be used on the camera. Anything from 9v to 10v is better and will last longer. I connected 8 NiMH cells in series that produces 10.6V without load. It drops to 10.1 when connected to GH2 with 100-300 lens attached. It drops to 9.7 for a few seconds after firing the built-in flash. I use the following voltmeter with that battery pack:
http://cgi.ebay.com/4-5V-30V-Blue-Small-Digital-Volt-Meter-No-need-Power-/170631703914?pt=LH_DefaultDomain_0&hash=item27ba712d6a

Good luck.

B3Guy
05-19-2011, 03:25 PM
good to know. I thought 10v was pushing it, no?

tyampel
05-19-2011, 04:15 PM
good to know. I thought 10v was pushing it, no?
The output of the power adapter for GH1 is stated as 9.3V. I have no doubts that the power circuitry in GH2 is the same as in GH1.
It does not make sense to make it different. Normally such circuits are designed to at least 5% (but usually 10) + or - tolerances.
The fact that at 8.37V the camera refuses to work clearly proves that 8.4V is not the nominal value despite the fact that Panasonic's own adapter produces the output close to it.
Assuming 5% tolerances at 9.3V nominal voltage gives us 9.765 safe upper limit. With 10% tolerance we get a value of 10.23V.
With this in mind I will continue to use my 8-cell battery pack. For the faint of heart I would say "stay below 10V if possible:.
Good luck.

B3Guy
05-19-2011, 09:29 PM
What about using a SMPS with an 8.4v batt, to bump things up between 9 and 10?

guyburns
05-21-2011, 12:06 AM
I use an 8.4v like you see in the very first post. Timed out at 8 hours.

What was the capacity of the battery? I don't think you have told us. Is it 4500 mAh, similar to the one used in the video you linked to?

Roberto Hapsad
05-21-2011, 03:48 PM
Messing with this expensive camera is too risky unless you have a wrecked GH2 to experiment with! When you see a battery with four terminals you can expect smart (logical) circuitry to be involved, not just charging circuitry, volts, and amp hours. Maybe some Panasonic tech will tell us how this works - but powering this camera involves more than basic electronics. I haven't read all the posts in this thread but I haven't even seen any reference to VA - possibly required by the camera during special functions or at startup. If someone does manage to solder something together that works I'm scared it might be something pretty brutal - only appearing to work because it has somehow bypassed the camera's sophisticated protective circuitry routines! I'd say the best power solution will indeed come to us via China. Until then, let's all take beautiful pictures and not look this gift horse in the mouth.

g.l
05-21-2011, 04:01 PM
but powering this camera involves more than basic electronics.

No it doesn't, plenty of people are running this stuff, some for a long time. The extra pins on official batteries are only there to authenticate the battery is genuine, an attempt by Panny to lock our 3rd party batteries.

Roberto Hapsad
05-21-2011, 04:57 PM
The extra pins on official batteries are only there to authenticate the battery is genuine, an attempt by Panny to lock our 3rd party batteries.
Hi g.I,
Where did you source the information about the extra pins?

g.l
05-22-2011, 03:43 AM
Hi g.I,
Where did you source the information about the extra pins?

Well known fact, bourne out by many experiments and those of us using our DIY DCC8 adapters with only two pins. I think 3rd party battery sellers have now cracked the protection scheme.

EDIT: from a quick (non-comprehensive) Google, it seems the pins may also be used to report the battery level, as 3rd party batteries apparently don't. Doesn't affect powering though.

EDIT2: reading a bit more (http://www.dvxuser.com/V6/showthread.php?242159-GH2-battery-13.99-on-Ebay/page5), those 3rd party batts just pretend to be DC (that's why no battery level is shown), so they probably just output more voltage on the 2 power pins.

Svart
05-23-2011, 12:01 PM
The extra pins on official batteries are only there to authenticate the battery is genuine, an attempt by Panny to lock our 3rd party batteries.

That's absolutely untrue.

The extra pins are serial communication for SBS battery status alerts and for the thermistor (tracks cell temperatures for safety and proper charging). 3rd party batteries do not handshake with the camera body nor provide GasGauge functionality. That's why you don't get the battery life indicator on screen, because the battery life info is coming from the authentic battery, not the camera. The charger is not a smart charger as per SBS specifications. It's just a columb counting circuit that watches charge rates and temperature over time. that's why it will charge a dumb battery like the 3rd party batteries.

3rd party batteries offer nothing more than a DC source and rudimentary safety features(over/under voltage and temperature cutoffs). That's it. Because of this, I'd expect their functional lifetimes to be lower than an authentic battery due to rather poor (dis)charge cycle regulation.

Now for some interesting information:

A lot of the 2nd and 3rd level Smart Battery charging ICs use the presence of the thermistor to sense if there is a battery installed. It would be interesting if someone would measure power consumption with and without 10k ohms between the T pin and ground to simulate battery presence to see if the camera changes power conservation modes or not.

B3Guy
05-23-2011, 01:19 PM
Why not open up a panasonic battery, take out the cells, and hook a larger battery into the circuit where the original cells were? Would this not provide the correct functions on the "extra" pins (whatever their function is)? Use an SMPS to tune the larger battery to what the original internal cells output. An expensive adaptor (cost of original battery plus a cable, SMPS, and whatever lipos/nimh/etc. you were using), but it would be "doing right" by the camera, no?

keylight
05-23-2011, 01:44 PM
Why not open up a panasonic battery, take out the cells, and hook a larger battery into the circuit where the original cells were? Would this not provide the correct functions on the "extra" pins (whatever their function is)? Use an SMPS to tune the larger battery to what the original internal cells output. An expensive adaptor (cost of original battery plus a cable, SMPS, and whatever lipos/nimh/etc. you were using), but it would be "doing right" by the camera, no?

Since Panasonic batteries are so hard to come by, I think it's a tough thing to sacrifice a functioning battery for this. I'm also not sure how one would hook up a larger battery (with 2 leads) to the four pins on the case, or how you would then go about safely charging the battery.

I have yet to see a photo of the pins on a DCC8, but I seem to recall reading somewhere (on this site?) that there were only 2 pins on the adapter. If anyone has a DCC8 and can take a photo the pins (and as a bonus, would be willing to crack it open and take a photo of the internal wiring) I think we might be able to answer some of the remaining questions.

What I don't get, is why some of those big ebay vendors don't make and sell their own version of the DCC8 - other than legal issues of course (not that this stops them from making batteries).

adolgin
05-23-2011, 01:55 PM
Hmm, the problem of using large capacity external batteries (DV batteries, 12-14V, etc.) is already solved, we are shipping the Power Plate (http://dolgin.net/Power-Lumix.htm)which can be ordered in different flavors depending on what kind of a DC power source you want to use. Getting a hold of a DCC8 adapter off course is still a problem at this poing :-(

keylight
05-23-2011, 01:56 PM
What was the capacity of the battery? I don't think you have told us. Is it 4500 mAh, similar to the one used in the video you linked to?

The battery is 4500 mAh. I'm updating the first post with this info too. Can't believe I forgot to include that bit of info!

34395

http://www.amazon.com/Speedpack-4500mAh-Ni-MH-7-Cell-Flat/dp/B0038LDMJE/ref=sr_1_2?ie=UTF8&s=toys-and-games&qid=1306180452&sr=1-2

Svart
05-23-2011, 02:06 PM
Why not open up a panasonic battery, take out the cells, and hook a larger battery into the circuit where the original cells were? Would this not provide the correct functions on the "extra" pins (whatever their function is)? Use an SMPS to tune the larger battery to what the original internal cells output. An expensive adaptor (cost of original battery plus a cable, SMPS, and whatever lipos/nimh/etc. you were using), but it would be "doing right" by the camera, no?


You could take out the old cells and replace them with higher amp capacity cells but you have many limitations that are based on the controller IC's design. Many watchdog/GasGauge ICs are designed for specific numbers of cells, either 1, 2 or 3 cells(mostly 1 or 2 cells for these small packs). Some will allow you to parallel up cells but you still have to conform to the max/min charge/discharge currents and voltages. If it's a panasonic IC, we may not have the ability to get those details since they commonly design ICs for their own use and do not publish specs at all.

Also, LI-ion charge controllers monitor each cell group for load. that means if your battery contains 2 cells, it monitors both cells. If you try to hook up an external LI-ion pack to the charge IC in the panasonic controller IC, it will not work.

keylight
05-23-2011, 02:08 PM
Hmm, the problem of using large capacity external batteries (DV batteries, 12-14V, etc.) is already solved, we are shipping the Power Plate (http://dolgin.net/Power-Lumix.htm)which can be ordered in different flavors depending on what kind of a DC power source you want to use. Getting a hold of a DCC8 adapter off course is still a problem at this poing :-(

I really like your solution, and if I had a ton of peripherals to use with my camera I'd consider getting it. But for the camera alone, it's just too pricey. That's not meant to knock your product or pricing model. Your gear is in a fairly specialized market which translates to higher production costs....

But there's nothing quite like putting a $10, 1 hour, DIY adapter into the camera and slipping 8 hours of power into my pocket.

g.l
05-23-2011, 02:33 PM
Very useful info Svart.


That's absolutely untrue.

I'd already updated my post before your reply (after a bit of Googling).


The extra pins are serial communication for SBS battery status alerts and for the thermistor (tracks cell temperatures for safety and proper charging).Good to know. The GH2 body of course doesn't charge batteries, but thermal monitoring (if used by the body) is of course a good idea.


3rd party batteries do not handshake with the camera body nor provide GasGauge functionality. That's why you don't get the battery life indicator on screen, because the battery life info is coming from the authentic battery, not the camera.Are you sure that's true of the GH2 specifically? It already does voltage monitoring to implement it's software-enforced 8.4V PSU cutoff point, so it may well monitor the battery V directly. And of course it wouldn't do this (or display it) if it thinks a PSU is connected.

Anyway, my point was that the additional pins are not required to simply power the body, as Roberto claimed.

adolgin
05-23-2011, 02:38 PM
Fair enough :-) It all depends on what gets you excited. The only thing I wanted to mention for everyone's benefit, is unless you have solid electronic background, and direct experience working with Li-Ion cells, batteries, and chargers, do not risk your camera by experimenting with the components and cells. It is just very easy for the things to go wrong in an instant. I do not mean to come across in the negative way or to talk down. If somebody has a specific question, please send a PM, I will try to answer. One general comment: Panasonic obviously designed the camera in such a way to prevent a common 8.4V DC power source from powering the camera externally. There is no way a 2 cell Li-Ion battery can deliver more than 8.4V DC power due do its electro chemical properties (Panasonic engineers know this too well). While many here experiment with the Ni-Mh RC batteries, unless you know what a freshly charged voltage is, you are risking the camera by potentially stressing its electronics with too high voltage.

g.l
05-23-2011, 02:46 PM
While many here experiment with the Ni-Mh RC batteries, unless you know what a freshly charged voltage is, you are risking the camera by potentially stressing its electronics with too high voltage.

I totally agree. We need to know what regulator is used so we can find out the safe upper voltage. Check out the circuit board (http://www.gh1-hack.info/wiki/GH2EncryptionAndDumpingInformation) Svart, can you spot the part? I tried but the scans aren't high-res enough.

EDIT: Few more pictures here (http://www.chipworks.com/en/technical-competitive-analysis/resources/recent-teardowns/2011/01/teardown-of-the-panasonic-lumix-gh2/).

Svart
05-23-2011, 02:51 PM
Are you sure that's true of the GH2 specifically? It already does voltage monitoring to implement it's software-enforced 8.4V PSU cutoff point, so it may well monitor the battery V directly. And of course it wouldn't do this (or display it) if it thinks a PSU is connected..

I doubt it's a smart battery monitor, it's likely just a comparator setup or an UVLO (undervoltage lockout) circuit. I also doubt it's strictly software enforced either. Smart battery systems rarely work open loop, it's usually a combination of battery controller and charge controller working in a closed loop with each other. They are designed to work independently from the system they power as a safety feature so that no software glitch can cause runaway charge cycles which would cause damage and possibly fires.

Generally smart chargers count columbs of charge independently of what the GasGauge says the battery is charged to. While the battery reports a "calibrated" charge percentage, the charging IC only really cares about alert flags from the battery controller. Alert flags are either warnings or some other battery status. The charging IC or host controller on the I2C/SMbus can also interrogate the battery for its status as well. Either way, the GasGauge reading is usually fairly close to the actual % charge.

Did I read that the camera body does NOT give you shutdown warnings when using 3rd party batteries? Smart batteries will send out an alert with low battery warnings at pre-determined levels of charge, I'm wondering if the body gets all of it's all of it's low battery warning from the battery itself. It seems like it should as there would be no point in having some kind of secondary voltage watchdog in the camera. This would explain why the cameras offer no shutoff warning.

Svart
05-23-2011, 02:55 PM
I totally agree. We need to know what regulator is used so we can find out the safe upper voltage. Check out the circuit board (http://www.gh1-hack.info/wiki/GH2EncryptionAndDumpingInformation) Svart, can you spot the part? I tried but the scans aren't high-res enough.

EDIT: Few more pictures here (http://www.chipworks.com/en/technical-competitive-analysis/resources/recent-teardowns/2011/01/teardown-of-the-panasonic-lumix-gh2/).


in this pic:

http://www.chipworks.com/media/wpmu/uploads/blogs.dir/4/files/2011/01/Untitled-7.jpg

it's the one on the bottom right.

It's surrounded by inductors so it's obvious that it's a switcher that produces many voltage rails.

It's common for these types of supplies to have UVLO(under voltage lock out) so that you do not have sagging voltage rails to the ICs when you try to power it from a supply that has insufficient voltage. They can accept a range of voltages usually though.

However, the part looks unmarked in the pic. Not sure if that's just a picture thing or if it's really not marked, but I've seen that before with proprietary ICs. Chances are good that it's a panasonic part made specifically for powering that family of processors. Not good odds of getting info on it though.

g.l
05-23-2011, 02:59 PM
I doubt it's a smart battery monitor, it's likely just a comparator setup or an UVLO (undervoltage lockout) circuit. I also doubt it's strictly software enforced either. Smart battery systems rarely work open loop, it's usually a combination of battery controller and charge controller working in a closed loop with each other. They are designed to work independently from the system they power as a safety feature so that no software glitch can cause runaway charge cycles which would cause damage and possibly fires.

The GH2 body doesn't charge batteries though.


Did I read that the camera body does NOT give you shutdown warnings when using 3rd party batteries?

I read the same. It sounds like the 3rd party batts just pretend to be DC adapters, I assume they have to have another cell to output more voltage. If so, then there's no reason for the body to issue any warning as it doesn't expect the voltage to change.

g.l
05-23-2011, 03:14 PM
it's the one on the bottom right.

Figures, it's the only IC not marked at all (or they painted it out). I've emailed Chipworks (who did the board scans) to see if they can help.

Svart
05-23-2011, 03:22 PM
It doesn't necessarily have to charge a battery to use a smart charger IC.

However, We don't know what that big IC is, it could have a full battery management system in it or it could just be a dumb power supply. It's obvious though that the unit can determine that a battery is present and what the charge % is. The SMbus(serial communication for battery status) is probably directly controlled by the CPU and the thermistor connection is likely connected to the power controller IC(in that picture).


LI-ion batteries have safety circuits to cut their outputs off in the case of over/under voltage. Even the cheap ebay ones have this at least.

So yeah, the 3rd party batteries just look like DC adapters so the body doesn't expect the sudden cutoff of the battery pack one it reaches it's lowest safe voltage and turns itself off.

B3Guy
05-23-2011, 10:50 PM
Hmm, the problem of using large capacity external batteries (DV batteries, 12-14V, etc.) is already solved, we are shipping the Power Plate (http://dolgin.net/Power-Lumix.htm)which can be ordered in different flavors depending on what kind of a DC power source you want to use. Getting a hold of a DCC8 adapter off course is still a problem at this poing :-(

Thanks for sharing this! Didn't even know that was out there! I'll definitely be saving up to buy this at some point! looks like it would make a great counterweight on the back of a shoulder rig. One question: there is an option when ordering for "output 2 configuration". what is this, an extra output? what for? (what could it be used to power. it is 7.4v as well?)

Roberto Hapsad
05-24-2011, 02:50 AM
...the additional pins are not required to simply power the body, as Roberto claimed.
Misunderstanding. I was saying the extra terminals show there's more going on than just powering the body. ie, don't mess around until you know what you are doing.

Call me conventional, but I rarely get out the soldering iron until I've sketched out a circuit. I haven't seen a circuit diagram on this thread! I hate to hear of fellow users just putting their shiny new GH.x to the smoke test!

Now, you wouldn't start shooting a movie with your GH.x without a script, would you?

I do realise this thread is for readers prepared to mess with their equipment. So, here's my parting comment - a standard, "Don't do this at home" spiel:

Unless you're quite happy to fry your camera, leave the electric bits up to Panasonic (who will respect your warranty) -or folks like Dolgin, who will be legally obliged to replace your camera (in most countries) if their accessories stuff it up.

g.l
05-24-2011, 04:02 AM
Misunderstanding. I was saying the extra terminals show there's more going on than just powering the body. ie, don't mess around until you know what you are doing.

We know what we are doing, we are simulating the DC PSU which is fully understood and doesn't use the extra pins. However we don't know the safe upper voltage limit, which is why I'm using a regulator to supply the same voltage as the PSU. I'm personally not happy cramming in a higher voltage until it's confirmed safe.

adolgin
05-24-2011, 05:39 AM
Thanks for sharing this! Didn't even know that was out there! I'll definitely be saving up to buy this at some point! looks like it would make a great counterweight on the back of a shoulder rig. One question: there is an option when ordering for "output 2 configuration". what is this, an extra output? what for? (what could it be used to power. it is 7.4v as well?)
In case you are looking to power an audio recorder or a small monitor with the same battery, the additional cable will allow for that. That extra device will have to be able to run on native DV battery voltage, which is commonly called 7.2V. In fact it varies between 8.4V and 6.5V as the battery is discharging from full to empty.

adolgin
05-24-2011, 11:40 AM
The battery is 4500 mAh. I'm updating the first post with this info too. Can't believe I forgot to include that bit of info!

34395

http://www.amazon.com/Speedpack-4500mAh-Ni-MH-7-Cell-Flat/dp/B0038LDMJE/ref=sr_1_2?ie=UTF8&s=toys-and-games&qid=1306180452&sr=1-2

I looked at the Amazon RC pack data sheet, it is a 7 cell NiMh battery.

http://dolgin.net/NiMh-cell-voltage.jpg

This is the voltage discharge curve for a typical single NiMh cell. The 7 cell pack that you use will have ~1.4V x 7=9.8V when fully charged (I highlighted the starting point of the discharge in red). In other words, the GH2 camera that is nominally designed for ~8.4V - 9V DC power is seeing ~10V every time a freshly charged NiMh pack is connected. Keep in mind that the graph shows a slightly loaded cell at .8A. In the case of GH2, that voltage is going to be even higher as the camera uses ~.3A to operate, or zero when turned off. NiMh cell voltage varies a lot depending on load, temperature, and charging.

keylight
05-24-2011, 07:43 PM
The 7 cell pack that you use will have ~1.4V x 7=9.8V when fully charged (I highlighted the starting point of the discharge in red). In other words, the GH2 camera that is nominally designed for ~8.4V - 9V DC power is seeing ~10V every time a freshly charged NiMh pack is connected.

Here's a repost of my battery test I originally posted in another thread, which jives with your research:


I used my DIY DWM-DCC8 adapter (http://www.dvxuser.com/V6/showthread.php?243760-GH2-DIY-DMW-DCC8-%28DC-adapter%29) for this test.

There have been questions (http://www.dvxuser.com/V6/showthread.php?245022-DMW-DCC8-9.3v-or-8.4v) about the viability of using an external 8.4v battery with the GH2. I hope the following video answers those questions.

I did a timelapse of the GH2 hooked up to an 8.4v rated battery AND a meter, to show what exactly is happening over time. The camera stayed on for just over 8 hours on a single full charge of the 8.4v battery.


http://www.vimeo.com/22251394

Here are the details: For almost 7 of the 8 hours the camera was recording at 720p. (I had to twice stop and delete the recording to free up space. This was done without turning anything off.) The LCD was on the whole time. The interval of the timelapse was 1 frame per minute.

The battery actually metered 9.93V before I started, but dropped quickly to 9.84v once I got the camera on and recording. Also interesting to note is that the camera shut off at 8.37v and the battery went back up to 8.64v. When I got back to check the test, I turned the on camera and the voltage dropped to 8.41v and displayed "this battery cannot be used" on the screen before shutting off.

guyburns
05-25-2011, 02:34 AM
An interim summary of the GH2's power circuitry:

1. Minimum voltage (via internal battery): still undetermined, but probably around 6.6 volts. Could be as low as 6.0 volts.

2. Minimum voltage (via DCC8) - 8.4 volts (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2345617&viewfull=1#post2345617)

3. Maximum voltage still undetermined, but users have reported up to 10 volts as safe: (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2341044&viewfull=1#post2341044

4. Max average power draw (from spec sheet) is 3.4 Watts. This is confirmed by Badpix (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2327768&highlight=badpix#post2327768) who powered the GH2 at 9.15 volts with current readings that ranged from 350-410 mA. Taking the average at 375 mA yields 3.43 Watts. The GH2 circuitry is assumed to be constant power, driven internally by switching circuits (see point 10).

5. Maximum current draw is about 800 mA under two conditions: at turn on, and immediately after using the flash (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2329479&viewfull=1#post2329479)

6. To power the GH2 externally requires a power supply that can provide 8.40 volts at 800 mA. Including a factor for margin of error, suggests an external AC supply should be rated at 8.6 volts DC at 1.0 Amps.

7. Running the GH2 from external batteries without a switching regulator means using 7 NiMH cells. Any more and the initial voltage when freshly charged may damage the GH2. This method is easy to implement (no additional circuitry), but is inefficient – you need a larger battery than expected. For example, Keylight powered the GH2 for 8 hours from an 8.4 volt, 4500 mAh pack. If all the battery capacity could have been used the run time would have been 11.5 hours ( assuming 3.4 Watts drawn at an average voltage of 1.25 volts/cell the average current is ~390mA, giving a theoretical runtime of 4500/390 = 11.5 hours). The inefficiency is due to the 8.40/7 = 1.2 volt cutoff (instead of the 1.0 volt cutoff used by the manufacturer when measuring the capacity).

8. By using a battery supply with higher voltage, and regulated by a switcher set to ~8.60 volts, almost all the battery power could be used, though ~10% of the energy would be lost in the switcher. Using 10 Eneloops, for example, (1.25 volts/cell, 2000 mAh), would yield a run time of about 6.5 hours. The disadvantage is – a switcher is required.

9 An optimum solution for external power would be to use a chip such as http://products.cui.com/adtemplate_child.asp?brand=v-infinity&p=46094&c=194683&catky=&subcatky1=&subcatky2=, embedded inside a DCC8. Such a solution would run from 11-32 volts at about 90% efficiency, and be short-circuit and thermally protected. An input diode may be required to protect against reverse voltage.

10. The info on this page (http://www.chipworks.com/en/technical-competitive-analysis/resources/recent-teardowns/2011/01/teardown-of-the-panasonic-lumix-gh2/) says that one of the power supply chips is a Rohm BD8963EFJ (http://www.rohm.com/products/databook/power/pdf/bd8963efj-e.pdf). This chip is a switcher (up to 88 % efficient) which provides 1.0 - 2.5 volts output from a 5 volt (typical) input. Absolute maximum input voltage is 7.0 volts, suggesting that between this switcher and the GH2's power terminals is additional circuitry that regulates/protects the voltage delivered to the GH2. Internal RAM (http://www.elpida.com/en/products/mobileddr2bare.html) requires 1.8 volts, suggesting it is driven from the Rohm switcher.

11. To simulate the effect of the GH2 on a power supply without having to connect a GH2, use a 10 ohm, 5 Watt resistor in place of the GH2. If the voltage stays above 8.4 volts, the power supply will almost certainly work when connected to the GH2. If you intend leaving the resistor in the circuit for more than about 10 seconds, use a 10W resistor, not a 5 Watt, otherwise it may begin to smoke.

3rd-Party Battery
I have pulled apart my third-party battery. Well, there goes the delusion I had of being able to add a simple circuit into a DCC8 to make the GH2 think a battery was in place. As well as two batteries in series, the battery case contains a small circuit board packed with components: 15 resistors, 10 capacitors, 5 transistors, 3 ICs, 1 inductor (marked 220), and 1 saw mark where I opened the case and partly sawed through one of the ICs. I'm not going to bother to try and trace the circuit. High-resolution images of both sides of the board and the two batteries can be downloaded from: http://www.mediafire.com/?4b21y4sy55gx61u

keylight
05-26-2011, 11:17 PM
Just a quick note....

The DMW-DCC8 adapter for the GH2 is finally in stock at Adorama. I forgot I had one back ordered (from several months back) and they sent me an email telling me it shipped.

I might crack it open once it arrives, to take photos and see if there's anything special going on inside.....

keylight
05-26-2011, 11:27 PM
An interim summary of the GH2's power circuitry:
I just linked to this great summary at the top of the first post. Excellent!

mslade
05-27-2011, 09:45 PM
Just a quick note....

The DMW-DCC8 adapter for the GH2 is finally in stock at Adorama. I forgot I had one back ordered (from several months back) and they sent me an email telling me it shipped.

I might crack it open once it arrives, to take photos and see if there's anything special going on inside.....

OH YEAH!!! Just ordered 2 and they have already been shipped.

Mark

adolgin
05-28-2011, 08:55 AM
Just added 12V-16.4V external power options (http://dolgin.net/Power-Lumix.htm).

http://www.dolgin.net/pp-swit-600pix.jpg

g.l
05-30-2011, 07:36 AM
Great summary guyburns.

I got a reply from Chipworks, but they weren't able to help without performing lab tests (which costs). The regulator IC does seem to be proprietary, or at least unmarked.

I've also been running my camera with the Texas regulator at 8.6V for a few days - it works fine with a short cable (~50cm) but it failed today with a 3m extension connected. I will measure everything shortly, but it looks like the 8.8V from the official PSU is a better bet. I'll also test a 10m extension.

tyampel
05-30-2011, 08:02 AM
I think it it safe to run the camera in the 9 to 10 volts range.
As I mentioned before the GH1 adapter is rated at 9.3 volts.
As stated on this page, the camera turns off at 8.37V, so there must be at least 0.5V safety margin.

g.l
05-30-2011, 08:59 AM
As I mentioned before the GH1 adapter is rated at 9.3 volts.

We don't know for sure that the bodies use identical power (but I agree it's likely). Have you actually measured the GH1 PSU output? That would be interesting.

But you're right that there is a tolerance anyway, because the PSUs vary a little. Anyone know what a realistic tolerance percentage is?

Svart
05-30-2011, 09:17 AM
The external power supplies won't vary much at all, especially switchers. Maybe hundredths of a volt from unit to unit.

The power supply in the cameras, and others like it, have input ranges so that designers have some flexibility in their usage. Because it's a switching device, the theoretical minimum input voltage is not much more than the maximum output voltage(accounting for some drop through the circuit, etc). However, most companies put arbitrary limits on the inputs through software or hardware.

tyampel
05-30-2011, 04:29 PM
[QUOTE=g.l;2349850]We don't know for sure that the bodies use identical power (but I agree it's likely). Have you actually measured the GH1 PSU output? That would be interesting.

The GH1 adapter puts out 9.55V. I have two adapters for the Sony FX820 DVD player (the model number is AC-FX-150) and a generic replacement from a Chinese seller on eBay.
The genuine adapter outputs 9.77V, the other one 9.22V.
I also have a Sony adapter/charger for their TRV series of camcorders. They are rated at 8.4V. The actual output was measured at 8.42V.
This would seem to be the safest one to use. I tried to extend the DC wire by 6 ft, and the voltage dropped below 8.4 resulting in a message that the battery is not recognised.
So I am not using it.

keylight
05-30-2011, 11:41 PM
[QUOTE=g.l;2349850]We don't know for sure that the bodies use identical power (but I agree it's likely). Have you actually measured the GH1 PSU output? That would be interesting.

The GH1 adapter puts out 9.55V. I have two adapters for the Sony FX820 DVD player (the model number is AC-FX-150) and a generic replacement from a Chinese seller on eBay.
The genuine adapter outputs 9.77V, the other one 9.22V.
I also have a Sony adapter/charger for their TRV series of camcorders. They are rated at 8.4V. The actual output was measured at 8.42V.
This would seem to be the safest one to use. I tried to extend the DC wire by 6 ft, and the voltage dropped below 8.4 resulting in a message that the battery is not recognised.
So I am not using it.

FYI, I measured the GH2 PSU a while ago:


I metered the adapter and it runs at 8.79v. When I connect the Adapter to the camera via my DIY DC adapter, the voltage drops to 8.70. The Amperage is 740mA, even though the adapter says the output is 1.2A. See posts later in this tread for a discussion....

daihard
05-31-2011, 03:30 AM
Not to stray to far from the main goal... finding a reliable "long" running power source. However, with very limited resources available where I am.
I am curious how to resolve my power situation without spending a to much monies.
I have several Lithium 2500maH - 3.7 (4.2 when charged, protected so they shut off at 2.75v), I use these for my high end LED bike lights.
I know the camera will shut off once power is under the 7v line.
When configured (4 Cells) should run a solid 8.4v - around 5000maH. I'm pretty sure this setup will work well.

On a side note, has anyone tried several 9v batteries in parallel yet? These are of course easy to get and around the right voltage.
Rechargeable:
Capacity 1200 mAh
Voltage 9 V
And if im in a pinch or remote location, I could buy some disposables.
Any thoughts? I was going to look into using 3 - 9Vs in parellel.

Svart
05-31-2011, 07:43 AM
[QUOTE=tyampel;2350129]

FYI, I measured the GH2 PSU a while ago: I metered the adapter and it runs at 8.79v. When I connect the Adapter to the camera via my DIY DC adapter, the voltage drops to 8.70. The Amperage is 740mA, even though the adapter says the output is 1.2A. See posts later in this tread for a discussion....


The camera will *draw* as much current as it *wants* from an adapter. Current cannot be *forced* into a device. The significance is that the adapter must have more current sourcing ability than the device it powers will demand from it.

tyampel
05-31-2011, 08:10 AM
Not to stray to far from the main goal... finding a reliable "long" running power source. However, with very limited resources available where I am.
I am curious how to resolve my power situation without spending a to much monies.
I have several Lithium 2500maH - 3.7 (4.2 when charged, protected so they shut off at 2.75v), I use these for my high end LED bike lights.
I know the camera will shut off once power is under the 7v line.
When configured (4 Cells) should run a solid 8.4v - around 5000maH. I'm pretty sure this setup will work well.

On a side note, has anyone tried several 9v batteries in parallel yet? These are of course easy to get and around the right voltage.
Rechargeable:
Capacity 1200 mAh
Voltage 9 V
And if im in a pinch or remote location, I could buy some disposables.
Any thoughts? I was going to look into using 3 - 9Vs in parellel.

9V should work and will be safe to connect.

Good luck.

g.l
05-31-2011, 09:24 AM
9V should work and will be safe to connect.

It depends what the fully-charged voltage actually is, it's usually higher than rated.

tyampel
05-31-2011, 09:31 AM
It depends what the fully-charged voltage actually is, it's usually higher than rated.
I think daihard means the standard non-rechargeable 9v packs.

g.l
05-31-2011, 09:44 AM
I think daihard means the standard non-rechargeable 9v packs.

My bad :).

daihard
05-31-2011, 09:48 AM
Well, I found some nice Lithium rechargeable 9v which would be the main "aim". However, if say someone was traveling... then some disposables would be a great solution.
Im going to relieve a few smoke detectors and give it a try... hope to not burn anything down :P

Svart
05-31-2011, 10:03 AM
The alkaline discharge curve is not like LI-ion as it drops off more quickly during discharge. You'd likely get less time than you think from alkalines that are not regulated. What needs to happen is using a regulator to drop a higher voltage array of alkalines to keep the curve more constant for longer time.

daihard
05-31-2011, 10:11 AM
I figured as much with regards to the disposables. The rechargeable lith I'll focus on. But the alks was an after thought if I'm in a pinch for power.
The GH2 stops round 7v, so 3-4 in parallel should give you at least 45m off the disposables. (Fingers crossed)
Reason I'm interested in 9v is because the Cells could fit in a battery grip quite easily.

tyampel
05-31-2011, 01:32 PM
I figured as much with regards to the disposables. The rechargeable lith I'll focus on. But the alks was an after thought if I'm in a pinch for power.
The GH2 stops round 7v, so 3-4 in parallel should give you at least 45m off the disposables. (Fingers crossed)
Reason I'm interested in 9v is because the Cells could fit in a battery grip quite easily.

For an external power the GH2 will stop at 8.37v. So with 9v batteries you will not utilize their full potential.

monkeyking
06-01-2011, 10:35 AM
34878So is it safe to run my GH2 on a GH1 charger/power supply via DCC-8 ?

keylight
06-01-2011, 02:32 PM
Got my DMW-DCC8 today. Very cheaply made. No cutting required. It opened using my hands. Just popped apart. Sad that it took so long for Panasonic to mass produce these....

And it is pretty much what we thought. Just two contacts used.

34634

34635

34636

Looks like they are using these resistors:

http://uk.digikey.com/1/1/4481613-res-1-0k-ohm-3-4w-5-2010-smd-erj-12zyj102u.html

34637

34640

Svart
06-01-2011, 02:40 PM
Interesting that they have a 2Kohm load on that board. Must need it for power supply stability or something.

I took the 10$ ebay battery I bought and disassembled and then gutted it. I removed everything off the PCB but a tantalum cap and reverse protection diode and soldered a lead/connector, just like that one in the pic, to the PCB and ran it out the bottom corner of the battery case.

It works great. I just hacked a small 5v switcher into a 8.5v output to use with it too.

Svart
06-01-2011, 03:10 PM
And based on the size of the resistor compared to the size of the wire lead, those look more like 1206 parts rather than 2010 parts.

g.l
06-06-2011, 11:22 AM
To follow up my last post, I tried my 3m DC extension cable again @ 8.6V, and today it worked. But the 10m extension needed 9.05V (unloaded).

When measured, the extensions droop briefly during the intial power-up, but quickly stabilise (but the camera has already seen the dip and rejects it).

Electronics gurus, what is the cause? Resistance of the cable? (the 10m measures about 1.5ohm) And what's the correct way to address this? More voltage works (and I guess 9.05V is safe), but would (say) a larger output cap after the regulator work instead?

Svart
06-06-2011, 12:48 PM
resistance yes, but might also be inductive/reactive. Since your power source is at one end of the cable and the load is at another end, the source sees a resistive and inductive path before having to charge the capacitors on the input of the camera while simultaneously needing to source all of the power the camera demands at once. This can cause a lag in time between where the camera demands a lot of power and where the switcher senses it's outputs drooping and increases output(propagation delay). Thicker wires can mitigate this when using long cables. Be careful though, long cables between the powersupply and unit can cause a condition where you get an inductive kick when making/breaking the circuit when it's under load(not turning off camera first, accidentally kicking out cord, etc). I would use the shorter DC cable and use a longer AC extension to the external supply.

g.l
06-06-2011, 01:04 PM
resistance yes, but might also be inductive/reactive.

How could I measure this? I only have a multimeter, but I really should get a scope.


Since your power source is at one end of the cable and the load is at another end, the source sees a resistive and inductive path before having to charge the capacitors on the input of the camera while simultaneously needing to source all of the power the camera demands at once.I see.


Be careful though, long cables between the powersupply and unit can cause a condition where you get an inductive kick when making/breaking the circuit when it's under load(not turning off camera first, accidentally kicking out cord, etc). I would use the shorter DC cable and use a longer AC extension to the external supply.This one worries me. I'm powering both cameras from the same regulator - it's a 3D setup (2 bodies), and both must be turned on at the same time, so that their clocks are reasonably in sync (required for frame sync, which is important in 3D). That only works if the cameras are already switched on before you power them, and they regularly need to be power cycled this way (as the clocks gradually drift).

Usually both bodies are within 1 meter of each other, but for some very distant shots I need to separate them much more to heighten the depth effect. That's why I will occasionally use a 10m extension cable for one camera, and they have to be on the power line (after my regulator). So I really need to check on any inductive kick, and some way to mitigate if it's a problem. Any ideas? The TI regulator has a 'soft start' (slowly ramping voltage up), will this help mitigate the issue at powerup?

Actually thinking about it, this could presumably also affect the power-up timing of the camera on the extension, that could be bad.

Svart
06-06-2011, 01:34 PM
The "softstart" function only works when the switching regulator is powering up, not the cameras. If you plug the cameras in first and then turn on the power to them, you should be OK. If the cameras are off before you unplug them I wouldn't worry.

The inductive kick should only be a major problem with fast plug/unplug situations. Using a snubber circuit, a TVS or simply a reverse biased zener(maybe 10v or so) should clip off the transients enough to not be a problem.

http://www.coilgun.info/theoryinductors/inductivekickback.htm
http://en.wikipedia.org/wiki/Inductive_kick

g.l
06-06-2011, 02:25 PM
The "softstart" function only works when the switching regulator is powering up, not the cameras. If you plug the cameras in first and then turn on the power to them, you should be OK.

Right that's what I'm doing, the cameras stay on (and stay connected) permanently, and I power-cycle the battery which feeds the regulator.


The inductive kick should only be a major problem with fast plug/unplug situations.Great, that normally doesn't happen, though with a 10m extension I guess someone could trip over it :).


Using a snubber circuit, a TVS or simply a reverse biased zener(maybe 10v or so) should clip off the transients enough to not be a problem. I'll look into those, thanks for the advice Svart. So I'd need a scope to measure inductive kicks? I guess a meter is too slow right?

Svart
06-06-2011, 02:30 PM
Yeah a meter would be much too slow, you'd need a fast storage oscilloscope to catch these transients. I was measuring some the other day in a product I designed with an 8ft dc cable and I was getting 25vdc peaks from a 15vdc. So the transients themselves were 10v above the source and 5ns in duration. I used a snubber circuit and it seems to have fixed it.

g.l
06-06-2011, 02:36 PM
I was measuring some the other day in a product I designed with an 8ft dc cable and I was getting 25vdc peaks from a 15vdc. So the transients themselves were 10v above the source and 5ns in duration. I used a snubber circuit and it seems to have fixed it.

Ouch. In my scenario, the regulator would get the kick, not the cameras right? Or does it depend which end of the extension is unplugged?

Svart
06-06-2011, 02:49 PM
What I measured was at the internal regulators in the device(under full load). This was fed from an 8ft cord (20ga wires), from a 15v SMPS power brick.

alspacka
06-27-2011, 01:17 PM
Really informative thread! I'm picking up a GH2 and will be doing some moving timelapses with it. Once i get my dcc8, i'll be using a 3d printer to create my own battery grip, hopefully with a shutter that will connect to the shutter release port (they have a standard stereo port for shutter release, right?). Once i can measure the gh2 it should be no problem. I've already 3d printed lens cases and hoods, so the tolerances are very tight.

I'll post progress should i go through with it!

35951

Boncrek
06-27-2011, 03:57 PM
Really informative thread! I'm picking up a GH2 and will be doing some moving timelapses with it. Once i get my dcc8, i'll be using a 3d printer to create my own battery grip, hopefully with a shutter that will connect to the shutter release port (they have a standard stereo port for shutter release, right?). Once i can measure the gh2 it should be no problem. I've already 3d printed lens cases and hoods, so the tolerances are very tight.

I'll post progress should i go through with it!

35951

That 3D printing of the battery grip will be awesome.
The 2.5mm port used for the remote shutter is the same port that is used for an external mic...just so you know.

alspacka
06-27-2011, 08:29 PM
yep. I'll have to unplug it when i want to use my external. I plan to have it as a semi-loose cable

g.l
06-28-2011, 02:40 AM
hopefully with a shutter that will connect to the shutter release port (they have a standard stereo port for shutter release, right?)

Nope it's not a standard stereo port, the GH's use a 2.5" 4pin socket that shares a stereo mic in with the remote (but the firmware doesn't allow you to use both together). The remote uses just 2 pins (with varying resistances to signify the shutter states). You can buy ultra-cheap remotes on Ebay.

alspacka
06-28-2011, 09:43 AM
would anyone with one of these great RC car batteries be willing to photograph it from the top/side/front with a ruler so i can start designing a battery grip?

http://www.amazon.com/Speedpack-4500mAh-Ni-MH-7-Cell-Flat/dp/B0038LDMJE/ref=sr_1_2?ie=UTF8&s=toys-and-games&qid=1306180452&sr=1-2


Thanks. If nobody can i'll gladly wait till mine comes in from amazon

tommyp
06-28-2011, 04:16 PM
I just put together an AC charger using an ac-L10a charger for old sony hi 8 camcorders.
http://cgi.ebay.com/AC-Adapter-Power-Cord-Sony-AC-L10A-AC-L10B-Camera-/170649589770?pt=Camera_Cables_Cords&hash=item27bb82180a

We have a bunch of them at work that have been retired. The black wire is the positive and the white striped wire is the negative.



I used these tips off of ebay. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260616435736&ssPageName=STRK:MEWNX:IT

and the panasonic DMW-DCC8

Really super easy diy. It supplies 8.4 volts or a little more and keeps the camera running in ac mode.

staticmotion
10-03-2011, 05:42 AM
Am I correct when I say that with the original DMW-DCC8 in the camera you can have a less strickt powersupply? So there is no need to have a powersupply that is exacly 8.4V but it can also be 12V (and at least 1000mA) and the DMW-DCC8 will regulate to the proper Voltage.

Thanks

adolgin
10-03-2011, 05:58 AM
No, it does not regulate voltage. You will smoke the camera applying 12V.

staticmotion
10-03-2011, 06:14 AM
Thanks for the quick responce, so the voltage must be between 8.4 and 10V (like mentioned in post 152)?

adolgin
10-03-2011, 08:18 AM
The voltage has to be above 8.4V for the camera to work. As far as the higher limit, there is no published specifications; 10V might be OK, but it is not clear if the camera electronics is being stressed out or not. The Panasonic AC adapter is just under 9V.

MarcusWolschon
10-05-2011, 05:44 AM
"It has been clearly shown (see Thread 3) that the voltage must be above 8.4 volts when the GH2 is powered via the DCC8 adaptor, otherwise it turns off. I"

I'm running my GH1 off a hacked 7.2V (6*1.2V) battery grip that was intended for the Canon 500D. Works well.
When my GH2 arrives and I get a DMW-DCC8 , I'll test that too.

MarcusWolschon
10-05-2011, 05:48 AM
Alspacka:
Do you have a design for your grip?
I have a draft for a printable GH1-grip and am working on a conversion kit to change some cheap
chinese Canon 500D grips into something that matches the shape perfectly (gripping the rounded edges)
and can be powered via external 5V USB or power other 5V devices.
(USB cellphone-batteries are so common these days and the Zoom H4n recorder powers fine from USB.)

MarcusWolschon
11-15-2011, 12:42 AM
So if we can't power a GH2 from a modified existing 7.2V battery grip, did anyone think about modifying the camera instead of the power supply?
It's not terribly difficult to take apart and re-assemble. (Had to do it with a GH1 already due to some chinese switching the meaning of red and black wires in a battery grip.)
Nothing needed but a household PH0/PH00 screwdriver and a few minutes of patience.
They don't even use terribly many types of bolts in there.
(One could even have a look at lifting the limiation of having EITHER an external microphone or an external shutter release button but not both.)


What if we give it a real battery to talk to but put diodes(to not charge the battery) and an external 7.2V supply onto the + and - contacts?
I have a dead china-battery in the workshop. ;)

tommyp
12-27-2011, 07:35 PM
I didn't read through the entire thread. But I have a few lipo Rc batteries at 14.4.

I am going to give this UBEC a whirl. Should be fine to connect and get the correct 9v voltage. I will test voltage when I get it but I am sure it will be fine.

http://www.hobbypartz.com/88e-9v-2-5a-ubec.html

daihard
12-28-2011, 01:09 AM
@tommyp (http://www.dvxuser.com/V6/member.php?54559-tommyp)
Ye, I saw that device as well. I was very curious about using it. I think it'll work just fine as well as be small enough that you can modify to fit inside a camera grip... which could be a nice DIY solution to what the guys are talking about earlier.

tommyp
12-28-2011, 07:35 AM
@tommyp (http://www.dvxuser.com/V6/member.php?54559-tommyp)
Ye, I saw that device as well. I was very curious about using it. I think it'll work just fine as well as be small enough that you can modify to fit inside a camera grip... which could be a nice DIY solution to what the guys are talking about earlier.

It will be totally fine. I use the ubec to power control boards on rc helecopters. They take 5v instead of 9v ubec but it is the same thing. You run your battery to power your motors and then step down whatever else you need with BECs.

keylight
01-08-2012, 07:38 PM
For those interested, I have tested and now use the Tekkeon MP3450i R2 battery with my GH2. It is a high-capacity lithium polymer battery, the best battery tech available.

45936

It allows a whole myriad of different voltage settings (via dip switches on the bottom). Just set it for 9V (the 8.4v setting gives a battery can't be used message after a couple of minutes) and you'll get a good 10+ hours of use. It comes with 5 tips, one which mates with the GH2 adapter perfectly.

They also sell a second battery without all of the connections so you can double up on the power:

45938

The extra battery is cheaper than the first, and includes the brackets to connect the two (the front bracket bridges the two together). Here's how it looks:




45937

There is even a third party 15mm rail mounting solution made by CPM Film Tools:

45939

All in all, an incredible setup!

monkeyking
01-09-2012, 07:58 AM
I would love to see photos of your rig; I would figure the extra batt. would be overkill? The 15mm rail mounting system is more elegant than leaving the Tekkeon on the floor : )

chris

adolgin
01-09-2012, 09:41 AM
You can order our Power Plate adapter through B&H (http://www.bhphotovideo.com/c/search?Ntt=dolgin+power+plate&N=0&InitialSearch=yes) now. While they did not put much information in the description, please look up on our own website here. (http://dolgin.net/Power-Lumix.htm) (Our adapter converts any common DV battery voltage to what GH2 needs to power up)

kopan
01-10-2012, 10:13 AM
How long does this battery work with GH2? I mean not set but just one battery? Can you plug in Lilliput monitor in the same time?

keylight
01-10-2012, 11:02 AM
The test I ran on a single Tekkeon ran for over 10 hours. To clarify, that was 10+ hours of actual recording time in 720p AVCHD, with the LCD on the whole time. I imagine if you used the small viewfinder instead you would get a longer recording time.

You can use the battery to power one device at a time. Would love it if Tekkeon made a battery that could power multiple devices at the same time.

adolgin: the power plate adapter looks cool, and definitely looks like a good option for someone with a lot of old DV batteries. Thing I like about the Tekkeon is that it is a lithium polymer battery. Li-poly batteries tend to be lighter and last longer than any other type of battery. Still, if you have lots of DV batteries around, then the plate adapter is probably more cost effective.

kopan
01-10-2012, 12:30 PM
Thanks for reply. I am thinking about GH2 right now because of price 1199. I want to sell my 60D setup so i have been making research about GH2 accessories and I know the biggest problem is with the batteries. But 10 hours is still enough for me :) I don't record more that 5-6 hours of material. Thanks again.

adolgin
01-10-2012, 12:38 PM
Keylight, the Tekkeons are popular due to their smart design, and overall quality - you are not only one who likes them a lot. But I need to clarify a common misconception when it comes to Li-Poly batteries. They have a great advantage of being easily shaped to fit custom products, making them so popular with the cell phone designers and such. But they do not have any inherent advantages over cylindrical or prizmatic cells that are used in the DV batteries. In fact if you compare apples and apples, and calculate WH/g for each (just do a math for Tekkeon - 50WH/433g =.115) while the Panasonic DV battery would be 39Wh/235g = .165. You can probably explain some of the difference in volumetric efficiency by the fact that the Tekkeons have a case that adds weight, still... they are not better or lighter. In fact, any full size DV battery is about 1/2 the weight of the Tekkeon, and will power the camera for about the same time.

keylight
01-10-2012, 02:16 PM
Keylight, the Tekkeons are popular due to their smart design, and overall quality - you are not only one who likes them a lot. But I need to clarify a common misconception when it comes to Li-Poly batteries. They have a great advantage of being easily shaped to fit custom products, making them so popular with the cell phone designers and such. But they do not have any inherent advantages over cylindrical or prizmatic cells that are used in the DV batteries. In fact if you compare apples and apples, and calculate WH/g for each (just do a math for Tekkeon - 50WH/433g =.115) while the Panasonic DV battery would be 39Wh/235g = .165. You can probably explain some of the difference in volumetric efficiency by the fact that the Tekkeons have a case that adds weight, still... they are not better or lighter. In fact, any full size DV battery is about 1/2 the weight of the Tekkeon, and will power the camera for about the same time.

Interesting. A few minor corrections to your figures. The Tekkeon I have in front of me weighed in at 436g and is rated at 58Wh, or .133 Wh/g.

I took a look at various DV batteries. They all output at 7.2V or 7.4V, but the GH2 requires more than that, doesn't it? Anything below 8.4 using the DMW-DCC8 and you'll get the battery can't be used message.... So are you pulling more than the rated output from the battery (didn't think that was possible), or tricking the GH2 into thinking it is getting what it expects?

Cheers!

adolgin
01-10-2012, 03:01 PM
Hmm, neither :-) We have a voltage converter/regulator circuit designed to fit inside the plate. So the output voltage is not the same as coming out of the battery, but is set to the level that GH2 is happy with. Also, we provide a second unregulated output (when ordered) so the same DV battery powers both a camera and a monitor, or any other accessory that uses ~7.2V.

JackBayer
01-10-2012, 04:22 PM
It just so happens, that I put my Tekkeon mp3450 on for sale in here (http://www.dvxuser.com/V6/showthread.php?272051-FOR-SALE-Tekkeon-MyPower-ALL-MP3450).
It doesn´t have the dip switches but you press the main button until the right voltage is selected, then you lock it, and THEN you connect it to whatever device.

//shameless plug

MarcusWolschon
01-10-2012, 10:51 PM
So no one has found a good buck&boost DC regulator chip yet that can output the voltage we need with a sensible input range at a sensible efficiency and needs only few external components?
(Like something you could integrate into a battery pack.)

Lolokia
01-13-2012, 02:23 AM
---------------------------------------------------------------------
UPDATE #2 (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2509223&viewfull=1#post2509223): I now use the incredible Tekkeon MP3450i R2.
Over 10 hours on a charge. More details in Post #201 (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2509223&viewfull=1#post2509223).
---------------------------------------------------------------------
UPDATE: In Post #152 (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2345804&viewfull=1#post2345804) guyburns put together a
GREAT summary of what we know as of 5/25/2011.
---------------------------------------------------------------------









There's a lot of information in various places on powering the GH2. I thought it might be useful to put links in one place. Hopefully this will help others in the future.

First, there's a DIY DC Adapter (DMW-DCC8) (http://www.dvxuser.com/V6/showthread.php?243760-GH2-DIY-DMW-DCC8-(DC-adapter)). The original idea is from Tyampel (http://www.dvxuser.com/V6/showthread.php?240093-dmw-dcc8-DC-coupler-where-is-it-in-stock&p=2261889&viewfull=1#post2261889). Another nice variation is from g.l. (http://www.dvxuser.com/V6/showthread.php?243760-GH2-DIY-DMW-DCC8-(DC-adapter)&p=2308383&viewfull=1#post2308383), who also had some useful tips.

33099

UPDATE: And now we know what the inside of a Panasonic DMW-DCC8 looks like. Full post here (http://www.dvxuser.com/V6/showthread.php?245907-GH2-Power-specs-tests-DIY&p=2351739&viewfull=1#post2351739)

34638

34639

Then, there is the DIY DC Power Source (http://vimeo.com/19591333). I made one of these and then ran it for 8 hours non-stop: Video Here (http://www.dvxuser.com/V6/showthread.php?245497-8.4v-Battery-test-results-(timelapse))

33102 (http://www.dvxuser.com/V6/showthread.php?245497-8.4v-Battery-test-results-(timelapse))

I used an 8.4v 4500mAh 7camera lensNi-MH flat battery for test.

Below is a photo showing the bottom of the Panasonic AC Adapter (DMW-AC8PP). I metered the adapter and it runs at 8.79v. When I connect the Adapter to the camera via my DIY DC adapter, the voltage drops to 8.70. The Amperage is 740mA, even though the adapter says the output is 1.2A. See posts later in this tread for a discussion....


33005

I've scanned the manual, but the site isn't allowing me to upload. Anyone know if there's a pdf file size limit (it's approximately 1.2MB)?


Last Edit changes: Added update to the top. Removed some quotes from later in this thread, as the link in the update summarizes everything best.

Wow, so cool, it's a good idea, i think that you must like thinking and action man.

g.l
01-13-2012, 03:08 AM
So no one has found a good buck&boost DC regulator chip yet that can output the voltage we need with a sensible input range at a sensible efficiency and needs only few external components?
(Like something you could integrate into a battery pack.)

I use a TI PTN78060W (http://www.ti.com/product/ptn78060w) to power two bodies from cheap 12V 4800mah Hong Kong batteries - only needs an external resistor to set the desired output voltage (with a trimmer you get a very flexible PSU), has a 'soft start' feature (output voltage is only enabled when the input stabilises and is ramped up), overheat protection etc. Not cheap (check Ebay) but works great, I used it in a plastic project case with no ventilation or heatsinking required.

For a single body you might also get away with the smaller PTN78000W.

12V batteries work best for me as I also want to power a 12V LCD preview monitor. If you don't need that you can also get the same type of batteries with 9V outputs (http://www.ebay.com/sch/i.html?_nkw=9v+5v+recharg*+batter*+-tester), prolly the simplest way to power a GH2.

Matthew P
01-13-2012, 03:54 AM
What about something like this (http://www.ebay.co.uk/itm/DC-DC-Converter-Regulator-12V-down-9V-2A-18W-Power-Supply-Module-Waterproof-/290653133684?pt=UK_BOI_Electrical_Test_Measurement _Equipment_ET&hash=item43ac46db74) along with a higher voltage battery? It says that it outputs 9v when being fed 12-24v, so if you used a 16v RC car battery, it would supply a steady 9v from fully charged to dry, right?

This could be even more flexible (http://www.ebay.co.uk/itm/LM2596-DC-Converter-Power-Supply-Buck-Step-Down-Regulator-In-4-40V-Out-1-5-35V-/170719990725?pt=UK_BOI_Electrical_Test_Measurement _Equipment_ET&hash=item27bfb453c5).

g.l
01-13-2012, 04:03 AM
What about something like this (http://www.ebay.co.uk/itm/DC-DC-Converter-Regulator-12V-down-9V-2A-18W-Power-Supply-Module-Waterproof-/290653133684?pt=UK_BOI_Electrical_Test_Measurement _Equipment_ET&hash=item43ac46db74) along with a higher voltage battery? It says that it outputs 9v when being fed 12-24v, so if you used a 16v RC car battery, it would supply a steady 9v from fully charged to dry, right?

This could be even more flexible (http://www.ebay.co.uk/itm/LM2596-DC-Converter-Power-Supply-Buck-Step-Down-Regulator-In-4-40V-Out-1-5-35V-/170719990725?pt=UK_BOI_Electrical_Test_Measurement _Equipment_ET&hash=item27bfb453c5).

The 1st one seems excellent on a 1st glance, cheap, sealed & good efficiency too. But it does seem to need 12V minimum, so if you're running it with a 12V battery that drops below 12V as it runs out, you may waste some useful time. For higher voltage batteries that's not an issue.

The 2nd only needs 1.5V higher in than the output, but doesn't mention efficiency.

Matthew P
01-13-2012, 04:54 AM
Might order one to experiment with.


But it does seem to need 12V minimum, so if you're running it with a 12V battery that drops below 12V as it runs out, you may waste some useful time.

What if one was to use two of these (http://www.ebay.co.uk/itm/8-4v-NiMH-5000mAh-Rechargeable-Battery-Vapextech-/220839261954?pt=UK_ToysGames_RadioControlled_JN&hash=item336b0bb702) in a series to double the voltage? You'd end up with a 16.8v battery (still 5000mAh?) with the capability to be completely drained by the GH2, correct?

g.l
01-13-2012, 07:38 AM
What if one was to use two of these (http://www.ebay.co.uk/itm/8-4v-NiMH-5000mAh-Rechargeable-Battery-Vapextech-/220839261954?pt=UK_ToysGames_RadioControlled_JN&hash=item336b0bb702) in a series to double the voltage? You'd end up with a 16.8v battery (still 5000mAh?) with the capability to be completely drained by the GH2, correct?

I guess so, but they seem pretty expensive for what you get, especially if you also need to buy a charger. Those Hong Kong Li-on batteries are pretty cheap on Ebay (www.ebay.com/sch/i.html?_nkw=12v+recharg*+lithium*), and they come with a charger & in various mah configs. Plus there are the 9V versions that you can use directly with the body.

MarcusWolschon
01-13-2012, 08:31 AM
I thought about using a conventional 7.2V battery grip or external 5V (because every external cellphone battery can give you 5V and they are usually not limited to 500mA).
Powering from higher voltage is easy.

Picturequest
01-14-2012, 03:17 AM
What is the Tekkeon's amps? How is its value compared to other batteries? I was going to buy 14.6v Capacity: 5000mAh for $29.

---------------------------

So I took a look at the battery on ebay:

This Rechargeable battery is a 12V 9v 5v Li-ion Battery and it is specially designed for powering the system device which use 12V 9v 5v DC power. You can use this battery to power our powerful wireless transmitter, CCTV camera and so on . Suitable for your need .

Dimension: 12 x 7 x 2.5CM
12V Dc: 6500ma
9V Dc:8500ma
5V Dc:15000ma
AC Adapter included 110VAC-240VAC to 12VDC $41

http://www.ebay.com/itm/New-Portable-12V-9V-5V-Li-ion-Rechargeable-Battery-Pack-/330531102264?pt=LH_DefaultDomain_0&hash=item4cf5305e38

Not a bad price with charger. Anyone use one yet? 8500ma @ 9v sounds like a long run time.

Do you think it outputs all 3 voltages at once? I could use 5, 9, and 12 volt!!!

found a youtube video: http://www.youtube.com/watch?v=iLJD0AKnO4U&feature=related

Matthew P
01-14-2012, 04:06 AM
I guess so, but they seem pretty expensive for what you get, especially if you also need to buy a charger. Those Hong Kong Li-on batteries are pretty cheap on Ebay (http://www.ebay.com/sch/i.html?_nkw=12v+recharg*+lithium*), and they come with a charger & in various mah configs. Plus there are the 9V versions that you can use directly with the body.

The problem with those cheap ebay ones is the questionable reliability, and likelihood of fire etc. I wouldn't touch them with a barge pole, personally, especially if it's going to be connected to a £740 camera!

Chinese manufacturers often overstate the actual mAh anyway, so it's often a false economy (or at least, less of the bargain that it seems).

MarcusWolschon
01-14-2012, 08:19 AM
I have two chinese ones for 10eur and one panasonic one that you get for 100eur.
Buy 3 batteries or one used camera.
For THAT price difference I rather change my batteries more often (no indicator) but have 2-3 spares.

Picturequest
01-14-2012, 11:00 AM
Well, I'm pretty sure all these devises with chargers or batteries, cables originate from China anyway?

Matthew P
01-14-2012, 11:53 AM
Well, I'm pretty sure all these devises with chargers or batteries, cables originate from China anyway?

Sure, but it's the quality control that differs considerably.

duartix
02-09-2012, 04:58 AM
For THAT price difference I rather change my batteries more often (no indicator) but have 2-3 spares.
Sure but the issue is that when you are doing timelapses or any other continuous recording, you just can't afford to swap them...

MarcusWolschon
02-09-2012, 05:12 AM
Sure but the issue is that when you are doing timelapses or any other continuous recording, you just can't afford to swap them...

Actually with the ownuser battery-grip you can.
One battery supplies the chip but does not get discharged very much while a second power source or battery supplies power and bridges the gap when you switch that second battery during a running video recording...

I just can't find the large version with the remote in Germany.
They only sell the small version here.

g.l
02-10-2012, 02:31 AM
The problem with those cheap ebay ones is the questionable reliability, and likelihood of fire etc. I wouldn't touch them with a barge pole, personally, especially if it's going to be connected to a £740 camera!

Chinese manufacturers often overstate the actual mAh anyway, so it's often a false economy (or at least, less of the bargain that it seems).

I'ts good to be cautious, but not all Ebay batteries are bad. My experience with Chinese batteries started with my HV20 - they were all fine, but didn't last very long (but I probably didn't use them enough, large gaps between shoots). The ones I linked which I use with my GH2s have been rock solid so far - they also hold their charge over long periods of use. My hunch is they are better quality, but I haven't burned through them enough to be sure. But neither type ever actually 'burned'. YMMV.

daihard
02-10-2012, 04:26 AM
Okay, I found the best solution for GH2 and frankly...many other camera model's power needs (since you can buy various UBEC voltages). MUCH cheaper then buying these $150+ power solutions. This works just fine for me, ive been field testing it for a few months without ANY issue. Also I live internationally, so most of my links are to international shippers.

I use a Lipo 14.4v 5000mah ($22.07) http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=15521
A UBEC ($5.27), which regulates ANY DC input (6V-23V) to 9V/2.5A http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=18785
Balance Charger ($11.18) - http://www.hobbyking.com/hobbyking/store/__8247__Turnigy_2S_3S_Balance_Charger_Direct_110_2 40v_Input.html

A 5000mah battery would probably give you continuous power for a few days... and these can be recharged in under 1hr!
On a side note. I AM NOT SURE that the UBEC can "up-convert", meaning, use any battery thats well OVER 9v. Hence, why i chose a 14.4v.

I used a nice "Tupperware" container (thick plastic with a clip on top), spray painted it black from the inside. Added a few key holes for cables and a strap to tie it down onto my shoulder rig.
I added a small window on the inside (not painted), so I can see the voltage left. These little devices run you about $3-5, and plug onto your battery pack. http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=22693

9v is a nice range, since most of my gear all runs off of 9v. My LED light and Zoom both can handle 9v. I bought a few high end R/C power leads and made a few Y cables.
There is a 12v UBEC I may get so I can power a LCD monitor as well. Even 5v and 6v ones, for the day when you can use an iPad for HDMI monitoring :P

Another thought was to buy one of these el cheap-o camcorder chargers. http://www.amazon.com/BP-819-BP-827-Compatible-Battery-Charger/dp/B003CQBS8M/ref=pd_vtp_p_1
Then gut it, and stick a UBEC inside. Rewire it, so you can use these larger camcorder batts. and power your unit.
That way, you dont need to worry about the "DIY" look to powering your rig.
Ill post pictures if anyone is interested. But the links should give you an idea of a good setup.

Dai-Lon

MarcusWolschon
02-10-2012, 04:45 AM
That 14.4V LiPo is heavier then the camera. That UBEC brand DC regulator doesn't state it's efficiency. What regulator chip does it use?
Still looking for a step up chip instead. If 1Kg+lens for a camera was okay for me, I'd use a full frame instead of an m4/3 in the first place.

daihard
02-10-2012, 05:13 AM
Pay for another "stock" panny battery then (you actually get pretty decent time off those for $50), cuz I promise you cant find lighter then the small UBEC module + ANY DC batt. 10v or higher (I'm also factoring in "simplicity" as im sure tons of people with electrical knowledge can make something similar... but $5 is hard to argue against)

You can use a lighter batt. 11.1v 2200 mAh is fine for hours of use too. http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=14487
The UBEC will regulate the voltage, and the power is "conditioned" so you wont be getting inconsistent voltage to your camera. As for it's efficiency, I cannot comment on that.
However, these are relatively efficient devices. As power and weight are at a premium in small R/C planes and helicopters. So i would "imagine" they are pretty efficient.
I can use a "199g" 11.1v 2200mAh batt for probably 5+ hrs. (i have a cheap 11.1v 2200mAh "mystery" battery, and have yet to drain it on a day long gig.)
All costing me less then $20 (batt and UBEC)... as I said before, its an "option" thats cost effective and... does the job.

I chose/recommend the larger batt. because on my shoulder rig, i can spare the extra mAh "weight" as well power multiply devices for many hours.
But for something more portable, you can find very light 11.1v and even "saddle" style batteries good for glide cam setups.

I bike a lot, so i also have MORE then a few 18650 Batts around (3.7v 2500mAh) and bought a 3 batt. holder for like $2. giving me 11.1v and I can also power my setup using that.
The reason i say this, is because you can wire these in almost any configuration and distribute the weight as you see fit. Heck you could find a batt. grip that fits the GH2 and fit like 4 of these 18650 batts inside.

My suggestion revolves around the UBEC, its small, light, simple, and effective. Its up to you guys to figure out how you want to use it. Pretty much any power source with decent mAh and over 10v DC will power your GH2 (drill batteries, car batttiers, old camcorder batteries, etc..
My previous recommendations fit MY needs, because I can monitor my battery's power, its easy and fast to charge, and provides the most power/mAh/weight ratio - per $.

On a side note, I have bought 2 chinese batts. Yes, its a solution. But if your covering an event like I do... long, dependable, continuos power is a MUST.
I think the main theme of this thread is solid, long lasting power alternatives. My chinese batteries I wouldn't use them any longer then 30mins, then id have to screw off my quick release plate, and pop in a fresh new battery. If the 3rd party battery dies mid capture... YOU LOOSE that footage. Its not a professional option one can risk.
Your shooting needs, and your budget will sort out your requirements in the end i guess.
P.S. Both my Chinese batts have reduced capacity now (6 months of occasional use), not to mention unreliable mAh to begin with. I started with about 1 - 1.5hrs of average use, and now on average, get less then 45mins from my Chinese "1600 mAh" batts.

M. Gilden
02-15-2012, 02:44 PM
Darnit.

I bought a dcc8 coupler since it was cheap enough to not warrant making my own adapter, but figured I could probably find one of my various AC/DC 9v adapters in the house that would fit it for running continously.

Turns out none of my adapters are the right size with the right voltage (one appears to fit, but doesn't make contact, its a bit too narrow).

I have a 2 hour shoot tomorrow night, so I quickly overnighted the following "universal" adapter with multiple tips from Amazon:
http://www.amazon.com/dp/B00068U44I/ref=pe_175190_21431760_cs_sce_dp_1

It arrived today. Guess what. Their "universe" doesn't include a tip my size. One is just too big and won't fit on, the next size down is the same as the other "too small" ones I found in my house. They make contact for a moment, but move the wire at all and it shuts off. What a waste of overnighted fees!

So, now the question is what to do for tomorrow night. I'm not a fan of Radio Shack's adaptaplug boxes (finding one with the correct voltage and amperage is a major pain in my experience), but I wonder if their tips are compatible...
Other option is to rip off a plug from another adapter that seems to fit and try to wire it up with some electrical tape- or perhaps wrap the "too small" plug with some wire so that it makes contact consistently. Both of those options make me nervous the more I think about them, though... :/

EDIT: Ok, I ended up ripping the odd-shapped plug off the dcc8 and splicing it together with one of the adapters for a 7" LCD I happened to have lying around (9v 2amps).
Will have to solder this thing eventually, but for now I twisted the ends together, wrapped each connection in electrical tape, and folded the wire back over itself, and wrapped THAT in electrical tape to hold it together. That way, if the wire gets tugged, the resistance won't go immediately to the connection. It should hold for tomorrow night at least. Actually, this seems more solid than the dcc8 does in general. :P

MarcusWolschon
02-16-2012, 12:50 AM
These plugs usually come in 1mm increments.
Panasonic used a non-standard size that is 0.5mm smaller.
You can get these but only in well sorted shops.
I ended up adding a connector compatible with the plug used in the GH1,
so I can use the same power supply for both generations.

JackBayer
02-16-2012, 02:58 AM
These plugs usually come in 1mm increments.
Panasonic used a non-standard size that is 0.5mm smaller.
You can get these but only in well sorted shops.
I ended up adding a connector compatible with the plug used in the GH1,
so I can use the same power supply for both generations.

I didn´t really read up, but your post caught my eye.
I found an ebay store, that offers compatlible adpater plugs, that bring you from a standard 12V plug to the DC coupler (Link (http://www.ebay.de/itm/230489661142?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)) and also to the H4n (http://www.ebay.de/itm/290446651882?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)(not topic related but anyways...)

MarcusWolschon
02-16-2012, 03:19 AM
Bad idea as the H4n runs on +5V .
I soldered myself a USB->H4n cable. Works fine.

JackBayer
02-16-2012, 03:28 AM
Sure, I use it with those cctv 12v, 9v, 5v batteries. Should have mentioned that... :)

daihard
02-16-2012, 05:31 AM
My zoom H4 runs off 9v. However I also used a USB power source and it runs on that as well.
Not sure about the H4n though.
I've got a 9v 4mAh, which I have split 3 ways. I'm running my GH2, Zoom H4, and LED C-160s lights all from the 9v power source. Not issues thus far.
As for a common adaptor tips, I've found some from old network hubs and routers. I also see that many universal laptop power supplie - tips will work.
You could also consider cutting the end and adapting a more solid connector for the GH2 adaptor. Many R/C stores sell some very solid connectors.

tommyp
04-12-2012, 08:44 PM
Finally remembered to purchase a 9v UBEC so I could run my GH2 off of the rc lipos I already own. Works great but I need to solder in a voltage meter so I don't run the battery down too much.

51814

M. Gilden
07-24-2012, 05:03 PM
Sorry to revive an old thread, but I'm wondering if anyone has had any experience with adapters such as these:
http://www.amazon.com/Lenmar-DVDU923-Universal-Battery-Portable/dp/B0011MZORU/ref=sr_1_6?s=electronics&ie=UTF8&qid=1343168588&sr=1-6&keywords=9v+external+battery

I was looking for those CCTV batteries that cheesycam recently wrote about, but they all ship from china and take weeks to arrive. I need an extended battery for a shoot coming up in 2 weeks, so I'd rather find something that will arrive sooner to test first.

keylight
07-24-2012, 05:59 PM
Sorry to revive an old thread, but I'm wondering if anyone has had any experience with adapters such as these:
http://www.amazon.com/Lenmar-DVDU923-Universal-Battery-Portable/dp/B0011MZORU/ref=sr_1_6?s=electronics&ie=UTF8&qid=1343168588&sr=1-6&keywords=9v+external+battery

I was looking for those CCTV batteries that cheesycam recently wrote about, but they all ship from china and take weeks to arrive. I need an extended battery for a shoot coming up in 2 weeks, so I'd rather find something that will arrive sooner to test first.

No experience with that one. It says it's a 9v power source, which might work. They're only 23Wh. That'll give you about the same amount of power as 2.5 Lumix batteries. Frankly, I'd get the switchable Tekkeon, which gives me 8 hours of record time with the LCD on. And you can use it to power devices with other voltages too, although only 1 at a time. (These are the voltages: 5V, 5.5V, 6V, 6.5V, 7.5V, 8.4V, 9V, 10V, 11V, 12V, 13V, 14V, 15V, 16V, 18V, and 19V)

In stock at B&H for $140: http://www.bhphotovideo.com/c/product/618847-REG/Tekkeon_MP3450I_myPower_ALL_Plus_MP3450i.html

M. Gilden
07-24-2012, 08:37 PM
No experience with that one. It says it's a 9v power source, which might work. They're only 23Wh. That'll give you about the same amount of power as 2.5 Lumix batteries. Frankly, I'd get the switchable Tekkeon, which gives me 8 hours of record time with the LCD on. And you can use it to power devices with other voltages too, although only 1 at a time. (These are the voltages: 5V, 5.5V, 6V, 6.5V, 7.5V, 8.4V, 9V, 10V, 11V, 12V, 13V, 14V, 15V, 16V, 18V, and 19V)

In stock at B&H for $140: http://www.bhphotovideo.com/c/product/618847-REG/Tekkeon_MP3450I_myPower_ALL_Plus_MP3450i.html

Nice!

But I was expecting to spend less than $80 on the batteries, especially compared to the $40 cctv ones were going to cost me. I don't mind paying more to get something in the US (since shipping from china isn't an option), but I'm really hoping there is an option for less than that Tekkeon!

Meanwhile, I found some other interesting options over on amazon:
http://www.amazon.com/15000mAh-External-Motorola-Portable-eletronics/dp/B0067XMPNY/ref=pd_ybh_14
or
http://www.amazon.com/EZOPower-High-capacity-Rechargable-10000mAh-Blackberry/dp/B005XQSN9G/ref=pd_ybh_11

then again, there are the RC car ones like the guy used here:
https://vimeo.com/19591333

keylight
07-24-2012, 09:37 PM
Nice!
then again, there are the RC car ones like the guy used here:
https://vimeo.com/19591333

That link is actually what inspired this whole thread. I used the same battery he used in my initial test (see the very first post in the thread for links). I got 8 hours. The battery eventually died and that's when I got the Tekkeon, which keeps on going and going.....

Again, don't know anything about the other batteries, but one possible drawback is the voltage setting is done via a push button. If you accidentally hit the button and up the voltage, you could fry the camera. The Tekkeon has dip switches on the bottom under a little rubber seal.

Still, for $60, they might be worth a try. If you do get one of them, I hope you'll report back what you learn.

Cheers!

M. Gilden
07-24-2012, 10:13 PM
That link is actually what inspired this whole thread. I used the same battery he used in my initial test (see the very first post in the thread for links). I got 8 hours. The battery eventually died and that's when I got the Tekkeon, which keeps on going and going.....

Again, don't know anything about the other batteries, but one possible drawback is the voltage setting is done via a push button. If you accidentally hit the button and up the voltage, you could fry the camera. The Tekkeon has dip switches on the bottom under a little rubber seal.

Still, for $60, they might be worth a try. If you do get one of them, I hope you'll report back what you learn.

Cheers!

Ah, I see that now. I have been doing enough research on this subject to go blind in one eye. I apologize, I have so many forum windows open that I lost track of which conversation each topic started in.

I have to admit, the RC battery thing scared me because I know that these batteries can read higher voltage when they finish charging for a little while, before they taper off into normal zones. I think I recall reading somewhere that a fellow attached a volt meter after charging and got 10+volts! That's far enough beyond the recommended 8.6-9v to make me nervous. But as far as it eventually dying- maybe I just don't understand the problem. They seem pretty cheap, why not buy another? You'd have to buy 10 of them to make up the cost of the Tekkeon, and all batteries eventually wear out. By the time you go through 10 RC batteries, who's the say the Tekkeon will continue holding a charge? :)

Seriously though, what happened to yours? Did it just refuse to charge after a while?

MarcusWolschon
07-24-2012, 10:20 PM
This works great:
http://marcuswolschon.blogspot.de/2012/07/panasonic-gh2-powered-via-usb-battery.html
No soldering, works out of the box. It powers my GH2 with 9V and 2 USB devices (e.g. my Zoom H4n with a USB-2-DC cable I made).

Still I would prefer a solution that adapts a battery cheap Canon 550D/... grip like with the GH1.
This is no solution for shooting handheld. Only for heavy shoulder rigs or tripods. ...and of cause only if you don't switch between handheld, tripod and shoulder rig at a moment's notice.

keylight
07-24-2012, 10:38 PM
This works great:
http://marcuswolschon.blogspot.de/2012/07/panasonic-gh2-powered-via-usb-battery.html
No soldering, works out of the box. It powers my GH2 with 9V and 2 USB devices (e.g. my Zoom H4n with a USB-2-DC cable I made).

Still I would prefer a solution that adapts a battery cheap Canon 550D/... grip like with the GH1.
This is no solution for shooting handheld. Only for heavy shoulder rigs or tripods. ...and of cause only if you don't switch between handheld, tripod and shoulder rig at a moment's notice.

So, it'll power 3 devices at different voltages at the same time? That would beat the Tekkeon.

I shoot handheld sometimes. I just use a longer cable and can strap the battery on (Velcro) or use a small camera pouch/bag to carry the battery on my belt.

MarcusWolschon
07-24-2012, 10:51 PM
Then make sure the DC plugs don't slip out during a shoot.
They don't lock in any way.

For photos it will probably work but for video I find that unacceptable as the connector may be pulled out by the slightest of forces any time and ruin the shot.

M. Gilden
07-25-2012, 12:02 AM
This works great:
http://marcuswolschon.blogspot.de/2012/07/panasonic-gh2-powered-via-usb-battery.html
No soldering, works out of the box. It powers my GH2 with 9V and 2 USB devices (e.g. my Zoom H4n with a USB-2-DC cable I made).

Still I would prefer a solution that adapts a battery cheap Canon 550D/... grip like with the GH1.
This is no solution for shooting handheld. Only for heavy shoulder rigs or tripods. ...and of cause only if you don't switch between handheld, tripod and shoulder rig at a moment's notice.

Holy cow! Its amazing that you just posted this! It appears that this is a popular OEM design that is being rebranded under a few different names. I *just* found this about 20 minutes ago:
http://www.amazon.com/Warranty-10000mAh-External-Battery-Charger/dp/B005NGKR54/ref=pd_cp_cps_0
as well as this:
http://www.amazon.com/EZOPower-High-capacity-Rechargable-10000mAh-Blackberry/dp/B005XQSN9G/ref=pd_ybh_11

I was just thinking to myself "I wonder if someone else has already tried and posted this model, because it might be under yet a different name so I wouldn't know".

Incredible! You've had good results with this, I gather? What kind of battery life are you getting, and how long have you had it?

MarcusWolschon
07-25-2012, 12:08 AM
I have yet to test the battery life in a long lasting video recoding with display and MF.

M. Gilden
07-25-2012, 12:18 AM
I have yet to test the battery life in a long lasting video recoding with display and MF.

Well why not?! If cheesycam considers this news: http://cheesycam.com/gh2-external-extended-battery-power-pack/

Your find seems like a better product, if only because it has the proper adapters included for less (especially if you already have the dcc8), and offers a battery life indicator! It might just be too late for me to think clearly at 2am, BUT THIS MUST BE PUBLICIZED!

MarcusWolschon
07-25-2012, 12:32 AM
Why not? Because I have many other things that are more important right now then doing a serveral hour video recording of something that moves.
Any because it's a blog posting it already is publicized. That's the point of having a blog.

keylight
07-25-2012, 02:49 AM
Then make sure the DC plugs don't slip out during a shoot.
They don't lock in any way.

For photos it will probably work but for video I find that unacceptable as the connector may be pulled out by the slightest of forces any time and ruin the shot.

There are two very simple solutions I use to solve that problem, and I never have a cable come unplugged. Both are shown in this photo:

57194

A velcro wrap (doesn't need to be tight, just enough so it holds) or gaffers tape.

But... you still haven't indicated if it'll power 3 devices at different voltages at the same time, or only one device (or multiple devices at the same voltage) at a time. The post you linked to doesn't say (just sort of talks about it won't last as long if it can). But if you have one, could you let us know?

And it's easy to do a time test. Point it out a window at traffic, zoom in a bit, turn auto-focus on, hit record. Come back 3 hours later, format, record some more. Three hours later, come back and format again, hit record. At some point the battery will die. Pop the SD card in your computer and see how long the clip is. Add 3 hours to that time for each cycle you formatted and you have your time.

That'll be accurate enough to tell you how long it lasts with the LCD on with motion and the auto-focus going. You'll end up getting better results if you use manual focus (as many people do when shooting video). That's basically how I initially tested the Tekkeon for 8+ hours, and sure enough, that's probably about what I'm getting.

MarcusWolschon
07-25-2012, 03:08 AM
No one would film long sequences with AF. The risk of it pumping when the light changes and ruining a 3+h shot would be too large.
When the battery dies, the last 2GB clip doesn't get finished and chances are that it cannot be reat anymore.