We have 500 watts of solar on our roof and 3 flooded batteries holding a max of 160 usable amps or about 2000 watts. With no shore power or gas generator power we can last a few cloudy days if we don’t run AC equipment (ACs, microwave, hair dryers, insta pots, etc). I could run my O2 concentrator for one night but then the batts would be almost unusable until we could recharge them. Remember RVs are designed to run on batteries and propane and no shore or gen power for a few days. In fact an Rv can run on its 12 volt system for weeks if you only run your propane ref/freezer and cook on the stovetop once or twice a day, a few led lights and keep your windows open for a it circulation. Add more 12 volt items or an AC inverter and you will be lucky to last more than a day.
In the winter only on batteries and propane running our central heater we can heat the Rv to 60 degrees for just over a day and a half if we are lucky. The electric blower fans can really drain batteries. We would still have propane for the heater but no power to blow she heat through the Rv. If we can run our main generator for just about 8 hours a day we could recharge the batteries to keep the Rv heater blower running. If no gen but we have solar and can keep the snow brushed off them they could keep the batteries charged. Assuming clear days with little or no clouds.
Note 1
For our rig with temperatures in the 20s outside we can keep temperatures in the mid 60s inside. If we have a power source for the blowers and change out a 30 pound propane tank every 4 days. If we improve our insulation some we might get an extra day on propane.
Note 2 I always keep both my solar, generator and battery bank in good shape. Plus I have a few extra propane tanks on the rig.
