BATTERY

The battery is the heart of all electrical system functions. It can and will be the cause of many problems and unit defects if not properly checked and maintained.

Today’s batteries are smaller and mostly of maintenance free design. They are for the most part very good, however they do have some inherent properties which can cause other system problems.

The first is that these batteries can’t recover from a deep discharge. A single deep discharge will lower the battery to only 80% of its original capacity. After three deep discharges the battery will have only about 50% of its original capacity. This lowered capacity will affect both starting and charging systems adversely.

Second, since the electrolyte cannot be check in most cases, load testing and static voltage testing with a good digital voltmeter is required.

1) Static testing : With a good digital voltmeter check the static voltage. If it is above 12.6 remove the surface charge by operating the headlights for 15 to 30 seconds and then recheck. A reading of 12.6 or higher indicates a full charge. A reading of 12.4 indicates 25% discharge. A reading of 12.2 indicated 50% discharge. A reading of 12.0 indicates 75% discharge. A reading lower that 12 .0 indicates almost complete discharge.

2) Load testing : As before, if voltage is above 12.6, remove surface charge by applying a 100 to 150 amp load for 10 seconds. Load test to 3 times the amp hour rating, or ½ the CCA rating for15 seconds. Voltage should stay at or above 9.6.

3) If you need to charge a battery try never to exceed a 10 amp charge rate. These newer batteries don’t take a fast charge and can be permanently damaged if charged at a higher rate. This requires slower charges for longer periods of time.

4) Ex. A 600 CCA battery with a static voltage reading of 12.2 would be approximately 50% discharged. Since ½ the CCA is 300, and 1/3 of 300 is 100, this battery is approximately a 100 amp hour battery. A 100 amp hour battery at a 50% state of discharge requires a 50 amp charge. If it is charged at 10 amps per hour it would take 5 hours to fully recharge!