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. Some manufacturers and retailers report that up to 50% of batteries returned under warranty are actually fit and healthy. Another interesting fact is that most people have met. The positive and negative electrodes (plates) in any battery cannot touch each other. If they do, they immediately short out and the cell dies. Note, this does not mean the entire battery suddenly becomes lifeless, it depends how. 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. When a lead acid battery discharges, the sulfates in the electrolyte attach themselves to the plates. During recharge, the sulfates move back into the acid, but not completely. Some. Acid stratification occurs in flooded lead acid batteries which are never fully recharged. This is especially common in vehicles which are used.
