Sulphation

When a battery has been left unaffended for a long period of time and has a specific gravity of less than 1.100, It will be completely discharged, resulting In sulphation on the cell plates.

Compared with a baffery discharged under normal conditions, the current flow In a "sulphated" battery Is not as smooth although its voltage Is high during the Initial stage of charging, as shown In the figure at the left.