Battery: Description and Operation

Battery Description

The battery has three major functions in the electrical system.

- It is a source of electrical energy for cranking the engine.
- It acts as a voltage stabilizer for the electrical system.
- It can, for a limited time, provide energy when the electrical load exceeds the output of generator.

Battery Carrier and Hold-Down Clamp

The battery carrier should be in good condition so that it will support the battery securely and keep it level. Before installing the battery, check that the battery carrier and hold-down clamp are clean and free from corrosion and that there is no foreign matter in the carrier.

Tighten the hold-down clamp bolts tight enough to prevent battery from shaking in its carrier, but do not over-tighten.

Electrolyte Freezing

The freezing point of electrolyte depends on its specific gravity. Since freezing may ruin the battery, protect against freezing by keeping the battery in a fully charged condition. If a battery is frozen accidentally, it should not be charged until it is warmed.

Sulfation

If the battery is allowed to sit for a long period in discharged condition, the lead sulfate changes to a hard, crystalline substance that will not easily turn back to active material during subsequent recharging. "Sulfation" refers to the result of this reaction as well as the process. Batteries in which this has occurred can be slowly charged and restored to a usable condition, but their capacity will be lower than the original capacity.

Built-In Indicator (If Provided)

The battery has a built-in temperature compensation indicator at the top. This indicator is used with the following diagnostic procedure. When checking the indicator, make sure that the top of the battery is clean. A light may be needed in poorly-lit areas.

The following three types of indication exist in normal operation.

- Green dot [A]
Battery is sufficiently charged for testing.
- Dark [B]
Battery must be charged before testing. If there is a cranking problem, battery should be tested as described in Testing and Inspection Battery Inspection. Charging and electrical systems should also be checked at this time.
- Clear or light yellow [C]
This means that fluid level is below the bottom of hydrometer. The cause may be excessive or prolonged charging, a broken case, excessive tipping, or normal battery deterioration. For barriers in this condition, a faulty charging system may be causing high charging voltage. Therefore, charging and electrical systems must be checked. If the battery is causing cranking problems, the battery should be replaced.