westend wrote:
IMO, I wouldn't gamble with my own health nor a child's by trying to overcome an RV battery issue by using an unvented space heater. Yes, most are perfectly safe when used according to the instructions but I think the science is yet to come out on what are safe levels of byproducts or oxygen in the enclosed space.
Again? :) ...
There has been a lot of science done about CO levels of unvented cat heaters vs unvented blue flame heaters in completely enclosed space, like in "airtight". I posted links to some scholarly articles earlier. Govt funded studies.
RV is not airtight, and yes, propane heater needs to be used according to the instructions. Like everything else. Don't remember, have to find it and read - one or two inches crack in a typical 3ft long window. You'll get poisoned more when driving on busy highway for several hours.
Quality CO detector, placed near your bed, will tell you the truth. The best model with alarm, numbers displayed and memory for peak readings will cost a whooping $60, no installation required.
Though it seems like OP should learn first how to charge batteries before the trip. 85 AH is not adequate, but it still shouldn't completely drain overnight down to 11.x volts with only furnace and fridge. That is - IF it discharged completely. I don't see any volts reported.
Ovenighting at 40F is not a "battery issue", it's a "goose down blanket issue" :B