The primary reason for the relatively short cycle life of a lead acid battery is depletion of the active material. According to the 2010 BCI Failure Modes Study, plate/grid-related breakdown has increased from 30 percent 5 years ago to 39 percent today.
The recovery of lead acid batteries from sulfation has been demonstrated by using several additives proposed by the authors et al. From electrochemical investigation, it was found that one of the main effects of additives is increasing the hydrogen overvoltage on the negative electrodes of the batteries.
The discharge state is more stable for lead–acid batteries because lead, on the negative electrode, and lead dioxide on the positive are unstable in sulfuric acid. Therefore, the chemical (not electrochemical) decomposition of lead and lead dioxide in sulfuric acid will proceed even without a load between the electrodes.
Such batteries may achieve routinely 1500 cycles, to a depth-of-discharge of 80 % at C /5. With valve-regulated lead–acid batteries, one obtains up to 800 cycles. Standard SLI batteries, on the other hand, will generally not even reach 100 cycles of this type. 4. Irreversible formation of lead sulfate in the active mass (crystallization, sulfation)
If at all possible, operate at moderate temperature and avoid deep discharges; charge as often as you can (See BU-403: Charging Lead Acid) The primary reason for the relatively short cycle life of a lead acid battery is depletion of the active material.
The lead within a battery is mechanically active. On discharge, the lead sulfate causes the plates to expand, a movement that reverses during charge when the plates contract again. Over time, sulfite crystals form that cause shedding of lead material.