[twindman]

I think the biggest draws are: A/C, then furnace or frig. If you don't need these things, then I think you can go all night with standard battery/ies. I have camped in Big Horns where temp was around 40 or below. My furnace draws down my 2 6V overnight by 7 or 8 am if I start it by 8 pm. Actually pretty dead at 5 am when starting at 7 or 8 pm (ask me how I know).