The Effect of Temperature on the Rate of Self Discharge of Lead-Acid Storage Batteries

Abstract

The rate of self discharge of starting‐lighting‐ignition (SLI) automobile batteries is compared at various temperatures ranging from − 2° to 47° C. It is expressed as the rate of drop of specific gravity of the electrolyte in the cells in terms of 0.001 specific gravity unit per day. From a value of 0.0012 to 0.0019 specific gravity drop per day at 26.7° C., this rate diminishes slowly to a vanishingly low value at about − 2° C. Above room temperature it increases rapidly to over 0.005 specific gravity per day at 47° C. At tropical temperatures the rate of self discharge of storage batteries becomes so rapid that it makes the retention of charge a problem of critical importance.