Here's what I did for an upgrade. I left the 30 amp OEM converter (wfco) in its little space under the power distribution center, and just disconnected it on the 12v and 120v sides.
ran two pieces of 3/4" conduit under the rv to the other side, inside a dinette bench.
installed four group 31 AGM batteries and a magnasine 2812 inverter + charger. the charger is 125 amps, 4 stage, power factor corrected and temperature compensated. it automatically scales back demand to make it compatible with a small generator or wimpy 15 amp outlet.