a7s external power?

impoze said:
Hey Olof,

that looks cool. How much for the dummy battery & plate?
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The price is $65.00 for the dummy battery a plate for a Sony 7.4v battery and the base for the plate with 2 4mm thumb screws that fasten to any cheese plate and has quick release L slots.

Standard cable is 12" long but you can order longer length as well, I will offer a 36" on the WEBstore as well, but I can make the chords longer. There is a 3mm jack at the end of the dummy battery, this is very good because if you yank the cable hard it just disconnects instead of ripping the cable out.

I will put this info with more photos on our WEBstore this weekend. You can contact me directly to order now if you like.
 
So here's the big question- will the A7s actually report battery life remaining with one of these?

The big issue with externally powering the Gh2 for me was that I had to keep track of how much battery I'd used- the camera wouldn't report battery life. So thankfully, the Anker power supply I opted for had an LCD display to tell me.

Since the Anker only outputs 9v (which I'm not convinced is safe to feed when Sony's own AC adapter feeds the camera 7.6v), I'm more interested in using Canon or Panasonic batteries, which I have plenty of. But then I thought I'd lose the battery status since that's how the GH series works.

This video, however, seems to show the battery meter at 100%:
https://www.youtube.com/watch?v=qGZMfAHQBEo

Oddly enough, he'd feeding it 9v. I have this battery supply. I just don't see how this is safe to do, though. Any thoughts on that as well as on-screen battery reporting?
 
 
As long is the battery is the correct voltage (and not those big 9v supplies that folks are powering GH cams with) this should be fine. But my question still remains- can you monitor how much life is left to the battery?
 
M. Gilden said:
So here's the big question- will the A7s actually report battery life remaining with one of these?

The big issue with externally powering the Gh2 for me was that I had to keep track of how much battery I'd used- the camera wouldn't report battery life. So thankfully, the Anker power supply I opted for had an LCD display to tell me.

Since the Anker only outputs 9v (which I'm not convinced is safe to feed when Sony's own AC adapter feeds the camera 7.6v), I'm more interested in using Canon or Panasonic batteries, which I have plenty of. But then I thought I'd lose the battery status since that's how the GH series works.

This video, however, seems to show the battery meter at 100%:
https://www.youtube.com/watch?v=qGZMfAHQBEo

Oddly enough, he'd feeding it 9v. I have this battery supply. I just don't see how this is safe to do, though. Any thoughts on that as well as on-screen battery reporting?
Click to expand...

My Swits report percentage just fine in the A7s, and they have LEDs on the battery was well.
 
Just wanted to update this thread with information I've found elsewhere:
Still trying to determine if it is safe to power the A7S with 9v, as we do GH cameras all the time and I have plenty of these battery packs already that I'd like to use.

It has been claimed that the A7s dummy battery adapter regulates the voltage like a UBEC down to the 7.6v a real battery would supply. An eager FB user cracked his open to check, and sure enough we found a little circuit inside. I'm attaching his image to illustrate:
a7s-dummy.jpg

Problem is, when someone attached a volt meter to it, it wasn't regulating the power AT ALL. His battery pack was outputting 9.3v, and the leads of the battery were outputting the very same 9.3v. That sounds dangerous, as its nearly 25% more voltage than the camera's internal batteries supply! I'm guessing that this little circuit board is an ID Chip, which will report to the camera that this is an official battery since most of these cameras required "chipped" batteries of some kind to operate. However, it is not regulating or reducing voltage at all.

The question is- is this a problem? Apparently, the official Sony AC adapter says it outputs 7.6v on the box, but a volt meter test from another user showed it outputting 8.4v. If that camera is designed to handle 8.4v, 9v might still be well within the acceptable operating range.
After all, the official Panasonic AC adapter outputs 8.4v according to the box, which we know is necessary because cameras like the GH2 need at least 8.4v in order to turn on without a chipped battery. The Gh2 community deduced from there that the Panasonic cameras use voltage to switch between "battery" mode and "external power" mode, where anything more than 8.4 is considered an uninterrupted supply like the AC adapter (hence no ID chip required or battery status on screen) and less than 8.4 is considered a battery and requires an ID chip to turn on and display power metering. Most devices have an operating range of 1v plus or minus the exact expected voltage due to fluctuations and spikes in batteries and adapters, so it was assumed that a 9v supply is safe to feed the GH2 if it expects 8.4.

The question is, does the A7S expect 8.4v too? The adapter tested seemed to be outputting that much, but that might have been a spike and still within the 1 volt of the expected 7.6v. Perhaps 8.4 is OK, but 9 would be pushing it?

I know people have demonstrated using their camera with a 9v supply. It turns on, and it works. But I'm not sure if this is slowly burning out the power supply in their camera. I remember a few people burnt out their GH2's mainboard trying to adapt alternative batteries to it, and I'd hate to find out our A7S's die in 6 months because we are over powering them. Am I thinking too much into this? Any insight or experience powering devices to share?
 
Was this one of the dummy batteries that came with a AC mains power supply that would have done the voltage regulation? They sell them on Amazon and lots of DIY DSLR people are using these but tossing away the AC power supply.
 
Andrew Stone said:
Was this one of the dummy batteries that came with a AC mains power supply that would have done the voltage regulation? They sell them on Amazon and lots of DIY DSLR people are using these but tossing away the AC power supply.
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Is that a thing? I think Sony's official AC adapter has the dummy battery hard wired to the AC/DC power supply box. The only dummy batteries with a plug are knock-offs sold separately as far as I can tell. Like all knock-off products, they're probably sourced from the same Chinese factory and are more-or-less identical. I've bought dummy batteries for my Panasonic cameras as well (both official and knock-off third party ones), and I've never, ever seen a dummy battery that actually regulated voltage. I feel like this is a rumor that started on a forum because the camera physically turned on with a 9v supply.
If anyone put a volt meter to the battery leads, I think they'd find that NONE OF THESE actually do that!
 
I still think the easiest, cheapest, safest way to do this is just to use a NPF battery plate and battery. This is what I'm doing, since the NP outputs 7.4v. A big NPF970 is enough for all day.
 
wallrc said:
I still think the easiest, cheapest, safest way to do this is just to use a NPF battery plate and battery. This is what I'm doing, since the NP outputs 7.4v. A big NPF970 is enough for all day.
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I was thinking about that, but I already own a ton of these for my GH cams, and they report how much juice is left so I can keep tabs on it throughout the day. How can you tell if your NPF is wearing out? Is there a way to monitor the battery in the camera, or does it just report 100% the entire time?
 
I actually have a bunch of Panasonic batteries from my DVX100 still in my closet (CGA-D54A). Seems like a good capacity and correct voltage. But I'm having trouble finding Panasonic battery plates, though. Plenty of Canon and Sony ones, but not so many Panasonic with a cable already attached (would rather not solder more things together to make a battery attachment, as I'm always afraid I did a bad job and it will come undone where I soldered).

Also, I'll still have the battery meter problem unless the camera does, in fact, correctly keep tabs on battery life remaining.
 
M. Gilden said:
I was thinking about that, but I already own a ton of these for my GH cams, and they report how much juice is left so I can keep tabs on it throughout the day. How can you tell if your NPF is wearing out? Is there a way to monitor the battery in the camera, or does it just report 100% the entire time?
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Mine seems to just report the battery like you'd expect it. It starts at 100% (usually - for some reason sometimes it shows 86% on a new battery) and then goes down from there.
 
wallrc said:
Mine seems to just report the battery like you'd expect it. It starts at 100% (usually - for some reason sometimes it shows 86% on a new battery) and then goes down from there.
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I'm guessing it relies on voltage to report life remaining. Problem with these 9v supplies that we are discussing using, is that they are regulated to deliver 9v no matter how much of a charge there actually is, so the camera sees more than what it considers 100% until the battery dies. If you feed it a battery that starts off fully charged at, lets say 7.6v, and it considers 8.4 to be fully charged, than it will start off showing you less than 100% capacity. And continue until the voltage drops to a point it can no longer stay operative, and therefore shut down the camera.

If this is actually how it works, I'd be happy enough with that!
 
Yes. The batteries I'm using are just plain old NP and deliver 7.4v. I expect at the voltage it's pretty accurate.
 
wallrc said:
Yes. The batteries I'm using are just plain old NP and deliver 7.4v. I expect at the voltage it's pretty accurate.
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Nice. Ordered my equipment, will see how this fares. It's been reliable enough for you so far? Someone asked me to help cover some live events. Hoping I won't need to invest in Sony batteries.

Also, where do you rig yours up? On a rail system or cage? I built something for my batteries to sit on in the past, but I'm wondering if there are better options.
 
Yes, the battery plate has a 1/4 on the back and screws into one of the holes on the cage. If you didn't have a cage you could just put it on a hotshoe mount if it was free. My plate came with a velcro loop as well.
 
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