We are storing our coach, 2008 Thunder, at a friends house and I want to reimburse them for the power I am using. The coach is plugged into a 30 amp outlet and the coach is under cover so no solar. We have a residential refer which we keep on and the batteries almost always shows just a float charge. I know there are some other items that are drawing power. I occasionally run two of the vent fans, the one in the kitchen and the one in the bath.