[Buddahaid]

Good question. I buy these replacement battery kits for Canon camcorders from Amazon which were $17.99 last time I ordered. They come with a charger that works on AC or 12 volt car adapter, and two batteries.








Then I modify the charger and batteries by adding a pair of wires to the battery connector, and half of a mini phone plug to mini phone plug cable.


The battery wires then connect to a switched mini phone jack such that when the plug is inserted, the battery positive gets disconnected from the circuit and connected to the charger. Remove the plug and the battery positive connects to the circuit. I usually have to do a little bending on the jack to make the switching reliable.




That's it. The nice thing about this battery is it's high AH rating, and if it fails sometime in the future, it can be replaced with a standard alkaline 9 volt.