Battery History: I have 4 (6V)Interstate batteries that are 6 years old and maintained with Xantrex GS Series Inverter Charger and ProFill watering setup on my 2000 HR Endeavor gasser. I typically sta...
You could also add a Battery Tender, or equivalent, that does automatic de sulfating. A battery not getting used in out/in duty cycles, can get after build up. De sulfating will help keep them a bit healthier.