Causes of Battery Failure
Major cause of premature battery failure is lead sulphation.  Using tap water to refill batteries can produce calcium sulfate that also will coat the plates and fill the pores.  Recharging a sulfated battery is like trying to wash your hands with gloves on.  When the active material in the plates can no longer sustain a discharge current, the battery “dies”.  Other causes of battery failure are as follows:

1. Deep Discharges
2. Vibration
3. Heat
4. Under-Charging
5. Non-Use
6. Over-Charging

In cold climates, normally a battery “ages” as the active positive plate material sheds (or flakes off) due to the expansion and contracton that occurs during the discharge and recharge cycle.  Brown sediment, called sludge or “mud”, builds up in the bottom of the case and can short the cell out.

In hot climates, additional causes of failure are positive grid growth, negative grid shrinkage, buckling of plates, or loss of water.

Accessible Batteries

1. Maintain correct electrolyte level- add only distilled water to within ½ inch from the top of the separator. The plates need to be covered with electrolyte at all times. Avoid over-filling especially in hot climates, because heat causes the electrolyte to expand and overflow.
2. Remove corrosion from both end of each battery cable and both terminals.
3. Clean the battery top
4. Check the alternator belt tension
5. Check battery hold-down.

The preventive maintenance frequency is dependent upon climate and battery type, but you should perform this at least once before cold weather starts and once a month in warm weather.