Metro, I like the idea of getting a battery and just using one cell; I agree with the limitations you cited, but in theory you could supply 3V to it and charge it too; just difficult to get 3V automatic trickle chargers, and would be less reliable. You could even get a junk battery with a bad cell; just don't use that one!
Orange4boy, I'm interested in how well your inverter - charger works - basically like a homemade DC-DC up converter, since you need AC to increase voltage (I think).
I'm going to look for said DC-DC converter and price it before I opt for the 8V golf cart batteries, since I've already invested in a really nice (optima yellow top) deep cycle battery. Wish I would've thought this ahead and realized the 12V problem.
Thanks!
Thanks for the info