batteies

Most likely your RV is set up for flooded batteries and doesn't have a lithium profile setting. The best option is to add a DC-DC charger that has a lithium setting for charging from both the AC charger and the alternator. This applies to trailers also as they are charged by the tow vehicle alternator. Solar is a third possible charging source.

MHs with 2 different type battery banks present additional changes for charging. Maybe as posted above, but it could also be an expensive lesson.