Sulfation

Discoloration of plates with white lead sulfate crystalline deposits may occur when the battery has been left for a considerable time in a discharged condition. It can also occur as a result of the plates being exposed to air due to low electrolyte level, or when a new battery is filled with acid and stored without being charged. This phenomenon is called sulfation. Once plates have been sulfated, the activity of the affected area is permanently impaired, and the battery may not be restored to its original capacity.