All rechargeable batteries degrade over time. Lead acid and sealed lead acid batteries are no exception. The question is, what exactly happens that causes lead acid batteries to die? This article assumes you have an understanding of the internal structure and make up of lead acid batteries.
Our area of expertise lies in industrial applications such as forklift truck lead acid batteries and we specialize in how to maximize the performance of the batteries to match and even reach beyond the life expectancy of the trucks themselves. In these applications the average guaranteed lifespan of a basic lead acid battery is around 1,500 cycles.
If lead acid batteries are cycled too deeply their plates can deform. Starter batteries are not meant to fall below 70% state of charge and deep cycle units can be at risk if they are regularly discharged to below 50%. In flooded lead acid batteries this can cause plates to touch each other and lead to an electrical short.
If you are not familiar with lead acid batteries, see our article What is a lead acid battery. Ironically one of the most common reasons for battery failure is not an actual failure of the battery itself, it is people thinking the battery is dead.
In both flooded lead acid and absorbent glass mat batteries the buckling can cause the active paste that is applied to the plates to shed off, reducing the ability of the plates to discharge and recharge. Acid stratification occurs in flooded lead acid batteries which are never fully recharged.
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.