Designing Portable Power for Camera

Archive SparkFun Site Questions/Comments
1

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 excessive 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.

2

You might try posting over in the technical side - posts here are more specific to the SparkFun website, so people who can help you might not see this here.

3

If the camera has a power jack (and you have or can buy the AC adapter) then you just need to measure the voltage supplied to the camera and average current drawn by the camera under the conditions of intended usage. This will require you to cut the power cable so that you can measure the current.

With that information, together with the proposed time period for unattended operation, it is straightforward to come up with an appropriate battery powered regulator.

4

Thanks much for the suggestion on measuring the power consumption and apologies for posting in the wrong area.