Im new to caravaning. Ive used my van for the last 3 weekends and I am delighted with it. Unfortunately I dont have a manual to refer to and Im trying to establish why the new battery is discharging. It caharges up fully when towing, but when Im on site hooked up to the electrics it doesnt seem to charge the battery. I put the caravan battery switch to the on position to power the water pump and leave it on. I switch the water pump off when not in use so why does the battery not automatically charge up? Is there something Im not doing? Any advice would be helpful.