Sulphation

—The deterioration of a storage cell due to the formation of lead sulphate over the surface of the plates. The lead sulphate is the product of the chemical combination of the active material with the electrolyte. It is a non-conductor, white in color and of greater volume, in proportion, than the active material. When the discharge of the cell is over prolonged, the sulphation is evidenced by the electrodes becoming lighter in color, because of the deposit of the sulphate which le ens the active surface, and, if further continued, by the loosening or breaking up of the active material or the ‘‘buckling”’ of the plates. Sulphation is usually the result of three principal causes: over-discharging, allowing the battery to remain discharged for a considerable time, or having wrong specific gravity of electrolyte.