I have a 04 dutchmen 27' travel trailer It has been sitting since the begining of november not plugged in or anything. I noticed two days ago the batteries were really week the lights would barely even come on. So I plugged it in with the adapter to plug in a regular cord about 9:00am this morning. I went back out about 5:00pm and the lights were still dead and barely even light up still plugged in. I checked the plugs and they all have power and the microwave time is on. I am not sure why it did not charge any and with it plugged in with the batteries completly dead why wouldn't all the lights still work. I then removed both batteries and brought them up to the garage and charged them up tonight and will put them back in tomorrow. I checked all the fusses and breakers and everything is good. Is their a fuse somewere else on like the invertor or something that could of blown. I am really confused. I would think regardless of the batteries being dead the lights and everything would still work being plugged in.