Eos 400D Dummy Batterie

I need to have my camera running for days (to shoot timelaps with an intervalometer)

I used this adapter to run the camera from a 12V wall adapter followed by a DC/DC converter set to 8.0V.

The contacts are made from short M3 screw. I filled the slot with solder an sanded the top back. The resistor is 10k and simulates the NTC-resistor in the original batterie.