dangerously cold weather RV heat

http://bdbud.com/stupid-rv-mistakes-1-winter-heating-battery/

Comment Quote: "Given that waking up dead is a real possibility with an external temp of -35C when cabin heat stops, I suppose that idling a gasoline engine is a rational response. In a crisis, we do what we can.

The solution is several things:

More house battery capacity,
isolated generator start battery,
Low-voltage cut-off to protect the battery bank,
non-electrified heat source like catalytic propane cabin heater,
improved insulation and heat-zone control in sleeping compartment to minimize furnace run-time,
CO & smoke detectors in cabin if engines (propulsion or gen-set) run while people are sleeping.

Plug-in to the municipal power grid when it’s so freakin’ cold!

Does your RV have block/oilpan heater to ease very-cold-weather starts, both propulsion and gennie, in case of 120v grid-power loss? Do your batteries have heatpad/insulation?

Upgrade cables to and from battery bank to high-drain items like refrigerator (if DC) or forced-air furnace/Air-Conditioning. Standard cabling in RV is as wimpy as is acceptable for certification. Stranded 8 gauge with heavy crimped ring-connectors tightly installed on clean terminals will reduce voltage drop at the load compared to “standard wiring” 14 or 16 gauge. Copper losses will also be much reduced.

If you have an inverter, thick & short DC cabling is a must. A 3000W 12v inverter needs at least #2/0 stranded copper and it shouldn’t be longer than 20′ long (loop length), IIRC. 24v and 48v inverters can make do with slightly longer runs, but also work best with thick and short copper between inverter and battery bank.

I would also look seriously at a few hundred Watts of roof solar panels/membrane and a good MPPT charger (as little as $199, made in USA) to maintain the expensive batteries in off-season. Betcha US$1000 would do this whole job if you are handy and a good shopper (and buy in the US via mail order).

I, too, have a stupid forced-air propane heater in my 1973 Timberline trailer. If the propane runs dry, the thermostat will run the fan at full-blast and attempt to spark the fuel (no fuel) until the battery is flat. Battery cut-off is set to 12.1v, and furnace is set to OFF each evening, but it *never* gets below about +15F in the Willamette Valley. Our solution is 4-season sleeping bags in the trailer -just in case-. unquote.