# What is the minimum connection required to power a digital camera externally?

I have a Canon compact digital camera Model IXUS70 which I want to use for time-lapse photography. The battery doesn't power it for long enough so I propose to gut an old battery and turn it into a power connector so I can externally power the camera indefinitely.

The battery has three connections:

labelled +, - and the third is unmarked, though I understand that this is a thermistor connection.

How should I connect this third pin, assuming that I am feeding 3.7 VDC into the + and - connections?

• It could be a one-wire protocol connection. If thats the case, then adding a dummy thermistor/resistor wont help, you might have to salvage the circuitry inside. Be careful with that thought, as cutting this battery up is a real fire hazard. – Wesley Lee Feb 26 '17 at 2:44
• The center terminal may not be required. thingiverse.com/thing:17437 – Bruce Abbott Feb 26 '17 at 6:12