RV Repair: 2005 fleetwood mallard battery problems, 12 volt batteries, amp chargers

Question
Hi, we have a 2005 mallard,that we store at the colorado
river.It gets used about 5 times a year.The original batteries lasted 3 years.We are always hooked up to power.I
bought 2 brand new 12 volt batteries and they drained down in 1 day.I also had low amp chargers connected to both batteries while in use.The trailer has a converter,battery charger.I would appreciate any ideas.

Answer
Mike, It sounds to me like the converter has gone bad. You can check it by using a volt meter at the fuse panel and read voltage. If the battery is down some you should have 13.4 volts trying to get back into them. If you have voltage there then look near the batteries to see if they have a circuit breaker in line before the batteries. If so check to see that voltage is getting to both sides of it. That is about all it should or could be. Thanks, Bill