Built-In Hydrometer

Built-in Hydrometer:

The maintenance-free battery has a built-in, temperature compensated hydrometer. The following is the battery diagnostic procedure using the hydrometer.

When observing the hydrometer, make sure that the battery has a clean top. A light may be required, when the lighting is poor.

Under normal operation, two indications can be observed.
1. Green Dot Visible - Any green appearance is interpreted as a "green dot" and the battery is ready for testing.
2. Dark; Green Dot Not Visible - When there is a cranking complaint, the battery should be tested as described in Diagnosis. The charging and electrical system should also be checked at this time. Occasionally, a third condition may appear:
3. Light Yellow or Clear indicator - This means the fluid level is below the bottom of the hydrometer. This can be caused by excessive or prolonged charging, a broken case, or excessive tipping. A battery in this condition may indicate high charging voltages caused by a faulty charging system. Therefore, the charging and electrical systems need to be checked. Do not test or charge the battery when the hydrometer is clear or light yellow; replace the battery.