If you learn that the current converter/charger overcharges and boils out house batteries, you may want to change to a modern one like the PD 9245 and replace house batteries.I replaced our two 6-volt Trojan T-105's with equivalent US brand batteries at $99 apiece. The Progressive Dynamics converter/charger works well, and is an easy DIY replacement project. I also installed a Trik-L-Start device which steals some charging current from the house batteries and keeps the starting battery up when rig is parked and connected to garage power in our driveway for long periods.