I had a similar issue with my American Eagle. To make a long story short I found that my battery disconnect relay needed replacing. When I pushed the disconnect button it gave every indication that it was in the off position. The connect light would turn off, you could hear the actuation click on the relay, yet when I put an amp meter on the battery is showed a drain on the battery. After replacing the relay, I inspected the old relay and discovered that the contacts were pitted from years of use and that the contactor was not releasing. The residual loads would drain the battery in short order. If you choose to leave the rig plugged in to electric, 30 amp is OK, just be sure that your charger is one of the newer types that will automatically adjust to a float condition once the battery is charged. Otherwise you risk overcharging the battery. I store my rig in the winter for several months in a spot where I do not have access to electricity. A single solar panel on the roof along with the charge controller is enough to keep the batteries in tip top shape and they do not get overcharged That was not the case before I replaced the disconnect relay. The constant residual load 24 hrs. a day exceeded the charge capacity of my single panel and the short winter daylight charge cycle.