[bushpilot]

on our coach -

the engine batteries are isolated (not charged by shore power or the generator).
the house batteries are charged (by the engine alternator) going down the road or at idle.

the house batteries are charged by 1) the converter charger (on shore power) and 2) the generator alternator (I believe) when it's running.

#2) above Im less certain of, since usually if the generator is running then the converter/charge is running too.

I would look for and test the isolation relay between the house batteries and chassis/engine batteries....If you don't have one, you should add it (theyre cheap).