Originally Posted by cadillackid
my battery data sheet shows that 10.6 is full discharge, and 10.75 is what they label as a soft floor.. are you saying i should never run them to 10.75?
generall I dont think ive ever run them below 11.5 under normal conditions but i also havent tried to run air conditioning on them either for any length of time
The actual numbers are manufacturer dependent, but @ ~12.0v (no load, resting) you're near 50% discharge, which is a commonly accepted figure for the max you'd want to drain them to on a regular basis if longevity is a concern. Granted there's no black or white answer, but the cycle life to discharge depth curve is similar to an exponential curve... As you (routinely) discharge deeper & deeper, your battery life shortens at a much greater rate. 11.5v is about 80% discharge, which is pretty much the max you'd ever want to discharge any to even on rare occasions. If you're routinely discharging to that level as a 'norm' you're murdering them slowly. 10.5 is dead, and hitting that level even once will result in damage you're unlikely to fully reverse. Me... I'd set up the battery protect to open at that 11.5 / 80% figure. I'd never go lower.