How to know if your car needs more power:
The condition of the cell plates inside the battery determines whether or not a battery is still serviceable. Current is produced when sulfuric acid in the battery reacts with lead in the cell plates. As the battery discharges, sulfate accumulates on the plates and reduces the battery's ability to make current. The sulfate is returned to solution when the alternator recharges the battery by forcing current to flow in the opposite direction.
Over time, some of the sulfate becomes permanently attached to the plates. The sulfate forms a barrier that…