Author Topic: Running Canon eos with dc power supply instead of battery?  (Read 6815 times)

Offline sorveltaja

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Running Canon eos with dc power supply instead of battery?
« on: January 03, 2023, 09:05:29 PM »
Just recently I bought a second-hand Canon eos 500D. I'm not a photographer, but wanted to get a camera with high resolution, that can be adjusted and released remotely via pc. Plus in these kinds of cameras it's easy to remove the lense out of the way, if needed.

For 45 euros I think it was a good bargain.

The camera came with a battery and a charger. When testing things, 1 or 2 hours battery life is rather short. And then waiting for another 1-2 hours for the battery to charge.

I found out that Canon dslr's don't seem to have direct dc connector, and require certain proprietary, model specific Canon dc-adapter and transformer -combination.

I looked on the net if there are ways to cheat the camera to think that the battery is in its compartment and charged, while being powered by dc power supply.

One suggested solution, that I found on the net, is to measure the resistance between fully charged battery's minus and "T"(thermistor perhaps) pads.

That's what I did (before disassembling the battery and making a 'dummy' version of it), and the resistance was about 10k. But in practice, connecting 10k resistor between those pads didn't work(at least in this model), resulting message "replace the battery" on a camera's screen.

It was time to test, what amount of resistance is enough. I used bench power supply with 8.1volts(that's what it says on the bottom of the cam) and several pots to see how the camera reacts to different resistance levels, and found that 1M(or maybe more) is, what seems to do the trick.

With 1M resistor the camera display shows that 'battery' is full.   

Dummy battery with printed top part. I used superglue with baking soda to make sure that the wires don't move around. The 1M resistor is inside shrink tubing:



So far so good, but I'll have to test some more to see if that solution actually works in the long run, as there may well be more undocumented sensors in these kinds of cameras, what comes to power supply.