Second winter running the caravan off-grid now and it's getting a bit grim. Running a Victron 2000VA MultiPlus with 400Ah of Fogstar Drift LiFePO4 and 600W of panels on the roof. Short days in [my location] mean I'm barely pulling 1-2kWh on a good day at the moment, which just isn't cutting it for heating.
Currently using a Hisense 9000 BTU mini-split as the main heat source and it's brutal on the batteries overnight. Even on eco mode I'm seeing 400-500W draw, which drains the 400Ah bank far quicker than I'd like. Wondering if I should be looking at a diesel air heater (Webasto or one of the cheaper Chinese units) as a backup for the really cold nights rather than flogging the inverter constantly.
Also curious whether anyone's had success with a hybrid approach — solar for daytime loads and something like a Propex or Webasto for overnight heat? The propex units look decent but the gas running costs add up. Is there a sweet spot anyone's found between cost, battery drain, and actually being warm?