clemsonfor
Super Member
If it dropped to 12.2 volts, and loses .5 v in a few hours, disconnected, it's just a bad battery.
they will settle down from the static charge pretty fast. If it rests at 12.5v it clearly has diminished capacity but I don't think that we can say just cause it settled down to its resting volts that quick its bad.
What you need to do is charge it up fully and then let it sit 8 to 12 hours, that's when you should take a reading, not an hour after you charge or whatever, see what you dropped too. If its only 80% of the battery capacity its not necessarily a bad battery if it starts your tractor or whatever at that voltage its just weak and has a diminished capacity.