Built-In Hydrometer

The sealed battery has a built-in, temperature-compensated hydrometer in the top of the battery. This hydrometer is to be used with the following diagnostic procedure:
1. When observing the hydrometer, make sure that the battery has a clean top.

2. Under normal operation two indications can be observed:
- GREEN DOT VISIBLE - Any green appearance is interpreted as a "green dot," meaning the battery is ready for testing.
- DARK GREEN DOT IS NOT VISIBLE - If there is a cranking complaint, the battery should be tested. The charging and electrical systems should also be checked at this time.

3. Occasionally, a third condition may appear:
- CLEAR OR BRIGHT YELLOW - This means the fluid level is below the bottom of the hydrometer. This may have been caused by excessive or prolonged charging, a broken case, excessive tipping, or normal battery wear. Finding a battery in this condition may indicate high charging by a faulty charging system. Therefore, the charging and the electrical systems may need to be checked if a cranking complaint exists. If the cranking complaint is caused by the battery, replace the battery.