Operation CHARM: Car repair manuals for everyone.

Built-In Hydrometer

Built-In Hydrometer:




On top of the maintenance-free battery is a built-in temperature compensated hydrometer. This hydrometer is to be used with the following diagnostic procedure.

When observing the hydrometer, make sure that the battery has a clean top. A light may be required in some poorly-lit areas.

Under normal operation, one of three indications can be observed:
1. GREEN DOT VISIBLE
- Any green appearance in the hydrometer is interpreted as a "green dot" and the battery is ready for testing.

2. DARK; GREEN DOT NOT VISIBLE
- If the green dot cannot be seen and there is a cranking complaint, proceed to "Diagnosis" for further testing. The charging and electrical systems should also be checked at this time.

3. CLEAR OR LIGHT YELLOW DOT
- This means the fluid level is below the bottom of the hydrometer and is too low for diagnosis. This may have been caused by excessive or prolonged charging, a broken case, excessive tipping or normal battery wear out. When finding a battery in this condition it may indicate high charging voltages caused by a faulty charging system. Therefore, the charging and electrical systems must be checked. The battery should be replaced if a cranking complaint exists and the battery has a yellow or clear hydrometer.