House battery/Propane

Not sure what kind of RV you have but generally with a motorhome the house batteries will charge in one or all of 3 ways, plugged into shore power, with the generator on, or the engine alternator. This is a general rule though and not applicable to every RV. There is also solar if your MH is so equipped.

As far as LP, a lot of campgrounds offer it, rv dealers, and places like tractor supply are the most common. Some truck stops.