Lead‐acid storage battery recovery system using on–off constant current charge and short–large discharge pulses

We report a method of recovering degraded lead‐acid batteries using an on–off constant current charge and short–large discharge pulse method. When the increases in inner impedance are within ∼20% of the initial impedance value, their system will permit discharge times to recover to a level approximately matching their initial time values. In one experiment, when the discharge time of a <5‐year‐old lead‐acid battery used for engine starting had degraded to about 50% of its initial discharge capacity, the authors found that 80% of the initial state discharge time could be recovered and maintained via their method. In a separate experiment, a deep‐cycle battery was forcibly degraded by 12 h of depletion at a constant current of 10 A discharged at a terminal voltage of 10.2 V. The results of that experiment show that use of their on–off constant current charge method for the deep‐cycle battery (recovered at 80% initial discharge time) quadrupled the post‐recovery discharge time in comparison with a battery recovered via constant voltage charge. Taken together, these results indicate that use of their proposed on–off constant current charge system can successfully recover both degraded engine start and deep‐cycle lead‐acid batteries.