The battery only holds a 14v charge when the alternator is feeding it... otherwise, the battery should hold 12.0 +-.5 volts when on its own... but that's rare. Even new batteries hold just below 12.0. Unlock your OBC and see what I mean. If I do Test 9 on OBC with car in Pos. 2, i get 11.98v which will slowly drop (with radio on, subs, etc) to about 11.4 until I turn it off. Even when running the car, my alternator makes abour 12.94v until i blip the throttle and then it will jump to like 13.86 - 14.09. I know these numbers by heart ever since I had alternator woes.