On Sun, 17 May 2009, Jim Coate wrote:
11.85 makes 1.98 volts/cell, which is happy as can be.Down to 11 volts under load is OK... one "rule" I've heard is 1.75 volts/cell minimum under load which is 10.5 volts on a 12 volt battery.
Under-load voltages are largely meaningless. THe voltage drop across the internal resistance depends on the current being pulled from the battery pack. So, you can get a pretty low "under-load" voltage from a fully charged battery if the current is high enough. And likewise, if you are only pulling a very small current from the batteries, a battery that is fairly dead can still have a decent voltage across it if the current is minimal.
Mike