Caution: Batteries produce explosive gases. Batteries contain corrosive acid. Batteries supply levels of electrical current high enough to cause burns. Therefore, in order to reduce the risk of personal injury while working near a battery, observe the following guidelines:

Molded into the top of the maintenance-free battery is a built-in temperature compensated hydrometer. Make sure that the battery top is clean when observing the hydrometer. Use a flashlight to observe the hydrometer in poorly lit areas. Do not produce any sparks. Use this hydrometer with the following diagnostic procedure.

Under normal operation, one of the following three indications will be observed:

1. The green dot is visible (A).

•	Any green appearance in the hydrometer is interpreted as a green dot.

•	The green dot means the battery is ready for testing. Refer to Battery Load Test .

2. When the green dot can not be seen (B). The charging is below 65 %.

•	If there is a cranking complaint, refer to Generator Assembly Check for further testing.

•	To check the charging system for excessive draw, refer to Battery Electrical Drain/Parasitic Load Test .

3. The dot appears clear or light yellow (C).

•	A diagnosis can not be made at this electrolyte level.

•	A clear or light yellow dot means that the electrolyte level is below the bottom of the hydrometer.

The following can cause a low fluid condition:

A battery found with a low electroyte condition can indicate a high charging voltage, caused by a faulty charging system. The charging system must be checked for specified output. Refer to Diagnosis of the Charging System.

Replace the battery when there is a yellow or clear hydrometer along with a cranking complaint.