On a recent boondock trip,I started with fully charged coach batteries. The first nigh my CO2 detector goes off.The windows are already open, I shut down the LPG.The next morning,aux batteries are completely dead.I have to use the engine to get enough power to start the gen. Ran it 4hrs,but an hour later they were dead. Charged them again, but hit the cut off switch. Couple hours later, guess what, DEAD! Anyone have any ideas?Please