Thanks Darol for the ideas for cold weather battery tips. We just spent a night at -26 in our stationary 79 Sovereign
and the (new) 40K furnace had to run all the time, never would have made it through the night without the Honda 2000. There are a few air leaks, mainly around the venting for the Univolt box. The Univolt wasn't working anyway and got removed a while ago, but the box was still in. After sealing the drafts my plan is to put the 2 group 24 batteries in sealed and vented boxes inside the heated area, and look for a small Toyo or similar that will draw a fraction of the 9.5 amps that the furnace uses. Of course we would need a true sine wave inverter to power a Toyo. Might even go with a non-electric LP heater. Have you heard of anyone else using an alternate heat source like this? We plan to use the trailer all winter and this seemed like a way to minimize need for battery draw. We are using the TT a few days every couple weeks and take the batteries home when we leave to keep them charged. We don't use the water system so don't have a need to keep pipes warm.
I have questions about the heat output of the furnace (85 degree air at -15 outside/+60 inside) but still have to research if that is normal.