I have just replaced all batteries. 8D for engine, and 6 GC2 6volts for coach. Also replaced inverter/charger with Freedom 2000 XC from Xantec. coach 12 volt lights will dim and furnaces stop working about every three days. Plugged in to 50 AMP shore power.<br/><br/>If I start engine before batteries get too low to crank, power comes back up to sufficient level to keep...