Thor Forums

[Ultra Limited012]

I have a new 2014 Thor Chateau 31A on a Ford E450 Chassis. I picked up my new unit in June of 2014 and while winterizing the unit in November I notice a problem with the Harris deep cycle battery. I was plugged into a 30amp outlet and the inverter was over charging the house battery to the point that in boiled it dry and damaged the plates to the point that the battery needs to be replaced. In researching this problem first of all I found the battery was probably as old as the chassis which was delivered to Thor in May of 2013. So by the time I bought the unit the battery was already 13 months old and probably had not been maintained per the manufacturers specs. Monthly check of fluids, charging etc. My second thought on this is that the house battery has a switch near the entry door that basically enables or disables the battery. If this switch is left on after you plug into 110V the inverter will continually charge the battery thinking it is discharging when in reality your 110V inverter is running all of the 12 volt systems. When I disabled the battery with the switch the inverter immediately stopped trying to charge the battery. The Harris battery is a fairly cheap install for Thor. I plan to replace this battery with an AGM sealed battery. AGM batteries can take over charging much better, resistant to cold freeze,, no need to add water, will not spill or overflow, resistant to shaking and movement issues and last much longer than standard lead acid batteries. I would think there would be a switch installed to prevent the house battery from being over charged if left on, but apparently not. It will also charge off the alternator when traveling, but I doubt it would overcharge from the alternator. One more weird setup is the front dash radio, DVD unit does not run off the chassis battery. It only runs off the house battery or the inverter being plugged in. To drive an use the in dash radio, you have to have the house battery switch in the on position.