DSLR Camera Power-supply Adapter (or Power-bank Adapter)

I like battery powered devices, I like my camera being portable. I don’t like not being able to use your device when the battery runs out. You can still use your laptop plugged in, same as your phone, your portable speakers, etc. Cameras should definitely be the same, more so when you consider the fact that their batteries tend to run out quicker every time as they get older, especially the cheap alternative ones.

I could buy a $20 dummy battery AC power supply adapter, but I (like most people nowadays) already have a bunch of 12V and higher chargers laying around, that can be used with one of those old cheap half-dead batteries I just mentioned, as a DIY power supply adapter for your camera.

Here’s how I did it.

Disclaimer: I made this specifically for my Canon EOS Rebel T4i camera, but the process should be pretty much the same in every camera. You just need to find out the power requirements for your specific model.

-Old camera battery

-Step-down voltage regulator LM2596

-DC female connector with cable (or a regular panel or PCB mounted connector, up to you)

-Wires

-Tape

-Any 12V DC charger, capable of at least 2A of current

Carefully open the battery enclosure with a screwdriver or a board cutter as shown in the pictures.

There will most likely be two 3.7V batteries inside wired in series to achieve the 7.4V required by the camera, so if you want to save them for a future project, be careful not to break them while opening the enclosure.

Once open, separate batteries from the small PCB board, this board is the most important bit of the project, so be careful with it too.

We’ll wire everything up as shown in the attached diagram. Make sure you adjust the regulator output voltage to the voltage required by your camera before you wire it to the battery’s board. You do this by turning the screw on the potentiometer and measuring the module output with a multi-meter. In my case, I needed 7.4V.

I wired the regulator output to the battery inputs (B+ and B-) in the battery’s board instead of the P+ and P- pins in the connector that goes directly into the camera. The voltage applied would be the same in both options, but using the battery inputs forces power to go through the board circuitry, thus using it as a quick over current / over voltage protection, in case something goes wrong with the regulator or the power supply.

After everything is wired up, plug the power supply to the DC female connector and check if you’re getting the 7.4V out of the battery board.

Before fitting everything together inside, wrap up the battery board with some electrical tape for isolation from the regulator. Also, if you’re using a DC connector with cable, make sure to make a little hole on the side of the enclosure for it.

All elements should fit almost perfectly inside, at least they did in the battery model I used (Canon LP-E8).

That’s it, you can go ahead and fit your new adaptor in the battery compartment of your camera. Remember to use a good power supply, good amperage and at least 12v output (9v might work too).

Get the polarity right too, very important.

You could turn this project into an adapter for a USB power-bank, or any USB power supply for that matter. You only need to change the step down voltage regulator for a step up board, because USB uses 5V, so you need to increase it to 7v. The issue here is that this requires more current, something that USB not always provides.

Just to be on the safe side, use a power-bank or power supply capable of at least 2 to 3A of current.

One last warning, most step up boards sold online use the XL6009 chip, which has been reported to output very high voltages (higher than 40V) when fed under voltages (less than 4V). This could definitely damage the adaptor, and possibly your camera. Always prefer modules that use the LM2577 chip.