Join Date: Aug 2006
Location: Arlington, VA
Thanked 11 Times in 9 Posts
Rep Power: 11
Thanks for that clarification, Dave. Lotsa folks don't discriminate between measured voltages UNDER LOAD vs. NO LOAD or no connections. Also, presumably, the charts for batteries under load refer to a 20-hour load only.
One other item: an hour or so isn't enough for a recently charged battery to lose its "float charge" and get down to 12.6 volts or so. Many batteries will hold a higher voltage for much longer. In my experience, 24 or even 48 hours is a safer interval to give a more accurate indication.
Note also that gells and AGMs exhibit higher voltages; those cited above are for flooded batteries.