While traveling, if you overnight at places where you can't plug-in (Walmart, Cracker Barrel, Cabellas, truck stop, etc), you will be unable to run your house systems without house batteries and inverter. That means no water, no refrigerator, no TV, etc. I will only use my coach batteries for starting and running the bus. If you're fine with staying in hotels and eating in restaurants while you travel and purchasing all perishable groceries after you reach your destination, I don't see a need for a house battery system. You'd simply have a cabin on wheels.