a7s external power?

M. Gilden

M. Gilden

Canon DSLR Moderator
Has anyone explored options for externally powering the A7S for hours like many of us did with the GH cameras and a big 'ol battery brick?

I've seen some folks online hook up a dummy DC coupler to the A7s and plug it into a 9v power supply, but that makes me nervous. The GH series' official AC adapter fed 9v into the coupler, so we knew the camera's voltage range was 8.4-9v at least. In fact, anything more than 8.4 told the thing it was externally powered, as exactly 8.4 seemed to throw the "not an official battery" error. But with the A7s, the official AC adapters that I found from Sony say 7.2 (I think?) output. That means these folks feeding it 9v may be overloading the poor camera's circuits. I'd imagine running it like this for an extended amount of time would be bad. Throwing this out there to collective mind- what say you?
 
I am almost done with a whole kit for the A7s.

One of the key parts is the external power. I use either Sony/Swit 7.4 v batteries or IDX/SB bricks converted to 7.4v to power the A7s.

I can supply just the dummy battery and plates with long cables so you can just keep battery in a pocket or on your own rig. Bigger batteries can even power recorder like the Odyssey as well as the camera and even a light.

You can contact me directly if you need the power solution. The whole kit should be done in the end of this month.

Photos are of a prototype a while ago.

FS7DevV11.jpg

FS7DevV12.jpg
 
I run the Switronix PB70 units on my a7S and a7ii and they are lifesavers. I can basically shoot all day with not a hint of worry.
 
I haven't used the Wooden Camera p-tap cable but the Switronix one linked above is significantly less expensive ($79 vs $125), incorporates the voltage regulator into the dummy battery so no extra box in the middle, and the coiled cable is helpful.
 
Interesting options!
Olof, I'd like to hear more about your solution. But it sounds like you are feeding it appropriately voltaged battery packs, which means the standard dummy battery floating around amazon and ebay would work find.

What I'm used to being able to do, is buy those standard 9v battery backup boxes and wire it directly up to my GH cameras, like this:

battery.jpg

I already own a few similar battery packs from doing multi-cam shoots to cover concerts, etc. I know the A7S won't record unlimited length without an external recorder, so I'm working on that as well, but I'd rather not also worry about swapping out batteries from the grip or keeping track of how much juice is left, especially if I had assistants monitoring those cameras. These battery packs can last anywhere from 5-8+ hours of continuous recording on my Panasonic cameras, and it doesn't seem like the A7 series draws more power. I just don't know if attaching 9v would fry the darned things.
 
tom1 said:
How long you can run with battery grip ? 3h ?
Click to expand...

It contains two standard Sony A7s batteries. Length of runtime depends on a whole bunch of variables. I would say 3 hours of runtime in record mode would be overly optimistic but you probably wouldn't be using a camera like this for event shooting. Many people carry 4 to 6 batteries for a day shoot but you may use more.
 
i have the same battery package... its 9 or 12 volt (switchable).
I would like to know if i can use it for my A7s.



M. Gilden said:
Interesting options!
Olof, I'd like to hear more about your solution. But it sounds like you are feeding it appropriately voltaged battery packs, which means the standard dummy battery floating around amazon and ebay would work find.

What I'm used to being able to do, is buy those standard 9v battery backup boxes and wire it directly up to my GH cameras, like this:

View attachment 94930

I already own a few similar battery packs from doing multi-cam shoots to cover concerts, etc. I know the A7S won't record unlimited length without an external recorder, so I'm working on that as well, but I'd rather not also worry about swapping out batteries from the grip or keeping track of how much juice is left, especially if I had assistants monitoring those cameras. These battery packs can last anywhere from 5-8+ hours of continuous recording on my Panasonic cameras, and it doesn't seem like the A7 series draws more power. I just don't know if attaching 9v would fry the darned things.
Click to expand...
 
toxotis70 said:
i have the same battery package... its 9 or 12 volt (switchable).
I would like to know if i can use it for my A7s.
Click to expand...

Yes. I have another one that can be digitally set to 9v-22v, its very useful as it can also power my laptop during a power outage, etc, and about 3 times the capacity of this one. Its also 3x bigger though.

Still, none of these can be set lower than 9v, which makes me nervous. I found someone online showing an A7s being powered by this and a dummy battery, but he's feeding it 9v. While it does work, I'm nervous about feeding it more voltage than it was designed to handle to an extended amount of time. I'm only comfortable with the GH and this solution because the official AC adapter feeds it 9v, so we know it can take it.

I'd consider a voltage regulator to turn this down before going into a dummy battery, but I've never really played with one or know how reliable they are.
 
My kits send 7.4v. Yes of course you can buy the parts on Ebay and put it together yourself. I buy the dummy batteries by the hundreds and I use the battery plates for many different solutions, so I buy those in quantity as well.

What I do is put it all together so it just works, and I combine it with my A7s kit. And that kit will actually have a wood handle on the right that makes the camera a lot more comfortable in the hand but still allows access to everything, and the shoulder part with the optional battery works with the built in WF. Any one with a milling machine even a manual one can make these parts. But not every one has CNC machines and want to program them. I also do a lot of custom building for shooters like myself.

I will post pictures here soon of the finished kit. It will also have an optional top handle for low angle shooting and balanced carrying.
 
atarijedi said:
WIth the battery grip, you can switch out the 2 batteries without disturbing the camera, as the grip has a small temporary battery inside it. If you really want external power though, you could use this > http://www.switronix.com/products?p...age=flypage.tpl&product_id=260&category_id=58
Click to expand...

Note that if you are talking about the standard vg-c1em. It has no internal short battery. For this reason I chose the movcam cage (not suitable for battery grip). And will be getting an atomos power station for true continuous Power (and power accessories).

The best you can do is to make a tape pull tab on one battery, wait till it's almost empty before it switches to the second, and replace it ( like bottom comment here ) http://www.sonyalphalab.com/product...ttery-grip-review-vg-c1em-for-a7-a7r-and-a7s/
 
This is my simple external power solution.

ExpwrA7s.jpg

I have this solution in stock now, I can furnish a long chord as well. This plate uses Sony 7.4v NP batteries like in the FS700. I can supply with Canon or Pany batterie plates as well. Kit uses a dummy battery. I can also sell you just the dummy battery, so you can hook up your own solution.

This is all part of the kit I am building for the A7s. If you are interested contact me directly. The whole kit including wood handle on the right will soon be available.

I just got my Shogun so I am now finishing up the kit including Shogun/Odyssey O7Q+ solid mounting system.
 
olof said:
This is my simple external power solution.


I have this solution in stock now, I can furnish a long chord as well. This plate uses Sony 7.4v NP batteries like in the FS700. I can supply with Canon or Pany batterie plates as well. Kit uses a dummy battery. I can also sell you just the dummy battery, so you can hook up your own solution.

This is all part of the kit I am building for the A7s. If you are interested contact me directly. The whole kit including wood handle on the right will soon be available.

I just got my Shogun so I am now finishing up the kit including Shogun/Odyssey O7Q+ solid mounting system.
Click to expand...
Cool stuff olof.

I a big DIYer personally (in the past, I've even built and soldered my own battery dummy for GH cameras because they weren't available yet).

For the battery pack I showed in the previous page, I actually built this accessory mount to supply continuous hours of power to a set of GH2s on a multi-cam show.
1512289_10154956426355254_9151378080695705409_n_zpsc2534587.jpg
The mount on the bottom can be switched out for things like a hotshoe attachment to sit on top of the camera, clamp for rail system, or beside/behind the camera, as I used it shown here:
10153003_10154956426500254_216442968752831606_n_zps4d73c12f.jpg

I already own a couple of these batteries, and their capacity is out of this world for this sort of thing. I can power a GH2/3/4 for 8 hours of continuous recording, and they have indicators on top that keep track of battery usage since the camera won't report how much juice is left. So really, ideally I'm looking for a solution to use these. But they don't go lower than 9v, so I'm concerned about this being unwise without some sort of voltage limiter (which I know very little about, but have heard of).

The truth of the matter is, your kit reminded me that I have a set of Panny batteries from my camcorder days, some pretty extended ones. They are the correct voltage it seems (7.2), so I guess I'd be good with a plate that accepts those and lets me run it into a dummy battery. The downside is that the capacity is not as large as the ones I currently use here for GH cameras, and unless I am mistaken, the camera will not report how much juice is left on the screen (or will it?). Since these batteries lack their own indicators, I just have to trust that it won't die in the middle of something important. Which is less than optimal for obvious reasons.
 
The safest way is to get specially made adapters as the battery is 7.4v, different from 12v and 14.4v, I saw a troubling review on the switronix a7s d tap adpter on b&h about electronic interference from the unit to the camera and decided to get wooden camera one instead. It's been working great so far.
 
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