common lead acid battery faults:

Careful treatment of lead acid batteries prevents damage and early failure, however, some common faults associated with lead acid batteries are:

Sulphation is the formation of hard, permanent lead sulphate on the plates and appears as random greyish white patches. Sulphation causes an increase in the internal resistance of the battery, leading to possible overheating and buckling of the plates.

Sulphation is caused by continually undercharging the battery or by discharging below 1.8 Volts or 1150 SG and is severe there is no cure, however if mild it can sometimes be cured by giving the battery a long low charge.

Buckling is twisting and bending of the plates. Because the active material is squeezed out of the plates the capacity of the battery may be reduced, if severe it can lead to internal shorting of the battery.

Buckling is caused by excessive charge and discharge currents being imposed on the battery and by the effects of sulphation.
There is no cure for buckling only prevention.

Sedimentation is the collection of discarded active material from the plates at the bottom of the cell.

Sedimentation may result in shorting of the plates and complete loss of capacity, slight shedding is normal in a well maintained battery.