When Milan-based engineer and photographer Andrea Biffi needed a constant source of power for his Canon 40D in order to shoot time-lapse photos over many hours, he decided to save some money by going the DIY route. Biffi turned a defunct lithium DSLR battery into a power supply unit that can be used with everything from a wall outlet to a car battery.
You can do the same thing at home, but you’ll need a bit of engineering know-how to accomplish the hack.
The main thing you’ll need (besides some tools) is a step-down adjustable power supply module that you’ll use to replace the guts of your battery. You can find them for a few bucks over on eBay.
Once you have the appropriate module, you’ll need to crack open your battery like a nut and remove the two lithium-ion batteries inside.
Then, drill a hole into the case for the new wires to pass through, and then solder the wires into the input and output terminals of the module.
After some adjustments and fine tuning — you’ll want to take steps to ensure that it works just right, lest you fry your camera — simply seal everything up, find a female plug, do some final tests, and you’re good to go!
That’s an extremely dumbed down explanation of what Biffi’s battery hack involves. If you’re serious about doing it yourself (and are sure you won’t kill either yourself or your camera), you can find a much more detailed step-by-step tutorial over on Instructables.
Cheap and Easy PSU for Canon EOS [Instructables]