I had run the batteries down to 12.1 I figured it was the bottom and never go below that. We had camped for 3 days and nights and used everything we wanted. We were on my brother in laws property and couldn't get the beast near the power pole to plug in. I just ordered a Honda 3000i. When we leave next winter I would think that I'd be running the gen each day and then at some point maybe after 2 weeks or so run it all day to bring the SG up but maybe it would be more like a couple of days. I like running the furnace because the Buddy heater messes up our sinus. I looked into the Cat Platinum but he said its a while before he will be building more of them. I consider the wave because of no battery use but I'm concerned about the fumes from it too. It aint easy RV'ing. I remember waking up on a deflated air mattress in a damp tent and it seemed easy. I know, it would kill me now.