For 1990-2009 cars

A hydrometer is built into the maintenance-free battery. The hydrometer is temperature-compensated. The color on the hydrometer indicates the condition of the battery.

Under normal operation, one of two color conditions on the hydrometer is possible:

• | A green dot or floating ball

• | A dark condition, with no green visible

A green dot on the hydrometer means the battery is ready for testing.

If the hydrometer is dark with no green visible, and there is a cranking complaint, inspect for trouble in the charging or electrical systems.

Occasionally, a clear or light yellow color appears. This means the battery fluid level is below the bottom of the hydrometer. A low fluid level can be caused by any of the following conditions:

• | A prolonged charge

• | An excessive charge

• | A broken case

• | Excessive battery tipping

• | A faulty charging system

Replace the battery if its condition affects the cranking system. Refer to Battery Replacement.