Your converter/charger is behind the house fuse panel. It takes 120v AC shore power or generator power and reduces and converts it to 12v DC. This not only powers all 12v house functions but is also a 3 stage charger for the batteries. According to the state of charge, it works at a high, medium, or trickle voltage to maintain and charge the batteries. It not only charges the house batteries but also the chassis battery. Likewise, when the engine is running, the engine alternator charges all batteries.
Section 6 of the
owner's manual.