Not Enough Juice! (Need Help with Coach Battery)

Phil/pnichols,

I assumed John's problem was that his furnace ran continuously during the night because the outside temp was so cold and his rig has a huge interior volume along with poor insulation & leaking in outside air through tired window & slide-in gaskets. But I see his pic and his rig is not that big, so I don't know what to say now in regards to his furnace running continuously.