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...
Doesn't really sound like you need 4. That's usually for folks doing a lot of dry camping. Get AGMs and you can dispense with the watering and hydrometers.