12. WHAT ARE THE MOST COMMON CAUSES OF PREMATURE BATTERY FAILURES?
Normally, premature battery failures are caused by one of the single failures listed below. Prior to 1980, plate or grid shorts were the most common failure. Since then the manufacturers have significantly improved the reliability by using improved separators and plate alloys to reduce corrosion. Batteries that have been in use for longer periods of time will typically fail from multiple causes. All batteries will fail at some point in time.
12.1. High under hood heat or overcharging causes a loss of water (which account for over 50% of the failures) and accelerated positive grid corrosion or grid growth causes plate-to-strap shorts.
12.2. Sulfation from water loss, undercharging, or prolonged periods of non-use. (Please see Section 16.)
12.3. Deep discharges (such as leaving your lights on).
12.4. Misapplication or using an undersized battery that causes discharges greater than 10%.
12.5. Excessive vibration due to a loose hold down clamp.
12.6. Using tap water causes calcium sulfation.