Sulfating

The lead sulfate on both the positive and negative electrodes in a lead acid battery results during the discharge portion of the charge / discharge cycle and is a normal part of the battery process. If the battery is allowed to remain in a discharged state for a prolonged period of time, these sulfate crystals continue to grow. These larger crystals reduce the effective plate area ands are difficult to dissolve back into solution with normal charging. Thus, they reduce the overall capacity of the battery. This condition can be prevented effectively recharging the battery immediately following a discharge. This condition can also be prevented by periodically equalizing the battery.