Hi Richard,

Thanks for the suggestion, but I'm afraid cell phone batteries, even the old bricks, won't meet my power requirements. In the end I'm going to need 24 volts at several amp-hours. I haven't come up with exact numbers, but if I want the thing to run for more than a hour between recharges (or battery exchanges), I'm going to need something like at least 3 amp hours. Once I know what's available I can make trade offs between weight/expense and runtime. Ideally, I'll have a battery set that will run the system for longer than it takes the recharger to ready a second set.

Thanks,
Joe