Bear Bagging

Interesting problem. If all you want to do is protect a small metalized bag or box, any fence charger is going to be gross overkill. The technology is there for significantly lighter options.
Think of a small stun gun, that instead of constant operation, only pulses about once every 3 seconds, but doesn’t produce an actual spark (aka dumb’ed down stun gun), just a lower voltage for a small part of a second. Thats basically what a fence charger is. (also realize though, that you have to drive a stake into the ground for a fence charger to work)
If there’s enough interest, I could build some of these that should run for several <dry> days on a single battery.

Regards,
Mike