Battery Dummy for Canon NB-7L

Overview

My Canon camera doesn't have an input for an external power supply, so I created a battery dummy. To power the camera, the dummy connects to a 7.5V power supply (make sure it's regulated!). The camera has a spring-loaded opening for the cable, so the battery cover can still close properly. 

Printed Parts

There are two printed parts: one battery dummy and one lid.

No supports, 0.4mm nozzle. I used PETG, but PLA should also work. 

Other Parts

• Blank or tinned/silvered solid copper wire, 1.5mm diameter (e.g. stripped PVC-insulated wire from a hardware store). Don't use enamelled wire.
• Two screws, 3mm diameter, flat head (countersunk). Screws for plastic or sheet metal work best, but M3 machine screws can be used in a pinch (use PETG with machine screws).
• Twin cable (cut off a broken “wall wart” power supply).
• A regulated 7.5V power supply with sufficient current capability (mine provides 1.2A).

Assembly

• Cut two lengths of the solid copper wire, approx. 30mm each.
• Solder one end of the twin cable to the two pieces of solid copper wire
  • If you can't solder, there should be enough space inside the dummy for a small terminal strip. The copper wires might need to be a bit longer for this method.
• Insert the copper wires into the two holes in the battery dummy. Make sure they reach all the way to the bottom (see 2nd photo).
• Bend the copper wires over.
• Make a loose knot in the twin cable (as a strain relief) and feed the cable through the hole at the other end of the battery dummy. Slide the knot over the boss (see 3rd photo).
• Screw the lid onto the battery dummy (4th photo).
• Connect the twin cable to the power supply. Make sure the polarity is correct (use a Canon battery for reference, see first photo)! Use a multimeter to double-check polarity before using it in the camera.