I have a 27k Hurricane and the use/store switch. I have concluded the electric draw is going wear down a battery in 24 hrs with little use of the lights and heater. The switch does not shut everything off, but does most. One of the draws is it powers up the invertor which you do not need when dry camping. I also have set my radio so the clock does not show but am thinking an on/off switch for it is even better idea. I bought another coach battery so I have 2, and still will be down to 50% power after a day. To solve this I bought a 100w 5.5 amp solar panel and charger controler from Home Depot
Grape Solar 100-Watt Polycrystalline Solar Panel for RV's, Boats and 12-Volt Systems-GS-Star-100W - The Home Depot and 20' of heavy wire using home style plugs for each end. I just plug it in when I set up and lay it in the sun, it keeps up with the demand pretty good. when I am stores it is in the back window. When stores I do put switch to store. My panel is wired direct to the batteries so bypass the switch. These units are self contained but in reality only for a day or so..