Portable Power for Camera

by weirdcat on Thu Dec 06, 2012 3:22 pm

I am need of powering a DSLR for extended periods outdoors in the winter, so portability is critical.

I thought about an off-the-shelf inverter along with the factory AC power supply, but this is somewhat more money than I wanted to spend. And, the inverter and AC power supply are huge which sort of kills the portability.

I would like to utilize different, large capacity, batteries anywhere from a 12v motorcycle battery to just a bunch of stacked AA cells that I can throw under a coat sometimes. I am not sure how to regulate these sources for the camera.

The camera uses 7.4v batteries that I've seen variants ranging from 1900-2500mA, but I don't know how many amps the camera actually draws or requires for normal operation.

Is this really just a matter of slapping together an LM317 with a proper resistor for 7.4v and not worry about things like current draw from the camera? If not, what exactly do I need, and are there any kits known to exist for this purpose?


Thanks much.
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Re: Portable Power for Camera

by adafruit_support_bill on Thu Dec 06, 2012 4:38 pm

Check the current rating of the manufacturer's AC supply. You will want something that can match that or better. A DSLR can easily pull several amps for short periods during focus and image processing phases. I use a 3rd party AC supply for mine and it is rated for 8v @ 3A. I tried running it from a 1.5A supply once. It would power up, but would shut-down as soon as I tried to take a photo.

Most DSLRs these days use LiPo packs. A 2-cell LiPo battery or a 6-cell NiMH pack will put out the right voltage and should not require a regulator.

(Of course the manufacturer will say that any electrons that do not originate from an authentic manufacturer supplied power source will invalidate your warranty and may damage your camera). :wink:
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Re: Portable Power for Camera

by weirdcat on Thu Dec 06, 2012 10:18 pm

Many thanks for the information. It especially helped knowing what did not work for you the first time!

Using this, and after finally finding what I think is reputable specs on the AC power supply as you mentioned, this should get me started in the right direction.
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