I just bought a used 4012 about 3 weeks ago. I plug my rv into shore power at the house. About a day or two goes by and the battery in almost dead. I started to notice that the lights would dim, as if they were running on just battery power. All of the items that I think run on some kind of converted power, like the radio, slides, lights, quit working. The battery was down to about 9 volts. I charged it and everything worked fine until the battery started slowly loosing power again. I still have stuff that runs off of strictly AC power (I think), like the plugs. It's as if nothing else is keeping the battery charged. Isn't there a power inverter that is supposed to charge the battery while connected to shore power? I have a manual on the power inverter with some suggestions on some diags to run, but I can't find the inverter. Does anyone know where this inverter might be located on a 4012? Am I going down the wrong path and should be looking at some other piece of equipment?