House Battery Charge While Underway

Back to the ops question I think what you are describing is normal. I have 2 6V batteries and 180 amp alternator and after a week of dry camping a five hour trip home won't completely charge my batteries. You have 4 6 V batteries and twice the amp hours to put back in those depleted batteries. With your motorhome running if you read 14 V at the chassis battery and 14 V at the house batteries your solenoids are working their way they should. It always takes me overnight to recharge my batteries with a 40 amp charger. Many on here talk about a larger wire size from the alternator to the batteries as being helpful and also external alternator regulators as a means of getting more amps to your batteries while driving. As far as parasitic draw's go these are easy enough to check by disconnecting your negative cable and putting your ammeter between the cable and the negative post I have .4 A of parasitic draw. I had over 1.5 A until I found what was causing these parasitic draws.