Additives - Are they worth it?

Since the 1950's chemical additives have been used in an attempt to reduce lead sulfate build up on plates and improve battery condition when added to the electrolyte of a lead-acid battery. Such treatments are rarely, if ever, effective. Two compounds used for such purposes are Epsom salts and Ethylenediaminetetraacetic acid(EDTA).

Epsom salts reduces the internal resistance in a weak or damaged battery and may allow a very small amount of extended life.

When EDTA is used to dissolve the sulfate deposits of heavily discharged plates, the dissolved material is no longer available reducing the specific gravity of the acid. The diluting the battery acid temporarily revived with EDTA will cause reduced battery capacity and reduced life. Residual EDTA in the lead-acid cell form organic acids which will accelerate corrosion of the lead plates and internal connectors.

The active material or lead paste changes it's physical form during charge/discharge resulting in growth and distortion of the plates. Shedding of the lead paste into the electrolyte results from excessive deep discharges and recharges. Once the lead paste has fallen off of the plates, it cannot be restored into position by any chemical treatment. A brown colored electrolyte is evidence of this condition. Similarly, internal physical problems such as cracked plates, corroded inter-cell connectors, or damaged separators cannot be restored chemically.