We had three converters in our original coach, two 12 Volt for the house, and one 24 volt for the chassis. We also had a 2000 watt inverter (not with a built in charger, just the inverter).
The converters as was pointed out were marine types and they not only charged the batteries, but if we chose we could also run all the 12 volt lights and devices from them. We never appreciated that particular feature until July 2004 when we lived in the coach for three days after our batteries quit working.