The battery has three major functions in the electrical
• It is a source of electrical energy for cranking the
• It acts as a voltage stabilizer for the electrical system.
• It can, for a limited time, provide energy when the
electrical load exceeds the output of the generator.
Carrier and Hold-Down
The battery carrier should be in good condition so that it
will support the battery securely and keep it level. Before
installing the battery, the battery carrier and hold-down
clamp should be clean and free from corrosion and
make certain there are no parts in carrier.
To prevent the battery from shaking in its carrier, the
hold-down bolts should be tight enough but not over-
The freezing point of electrolyte depends on its specific
gravity. Since freezing may ruin a battery, it should be
protected against freezing by keeping it in a fully
charged condition. If a battery is frozen accidentally, it
should not be charged until it is warmed.
If the battery is allowed to stand for a long period in
discharged condition, the lead sulfate becomes
converted into a hard, crystalline substance, which will
not easily turn back to the active material again during
the subsequent recharging. "Sulfation" means the result
as well as the process of that reaction. Such a battery
can be revived by very slow charging and may be
restored to usable condition but its capacity is lower than
Built-In Indicator (If Equipped)
The battery has a built-in temperature compensated
indicator in the top of the battery. This indicator is to be
used with the following diagnostic procedure. When
checking the indicator, make sure that the battery has a
clean top. A light may be needed in some poorly-lit
Three types of indication available under normal
operation are as follows.
• Green dot
Battery is sufficiently charged for testing.
Battery must be charged before testing. If there is a
cranking complaint, battery should be tested as
described in "Battery Inspection". Charging and
electrical systems should also be checked at this time.
• Clear or light yellow
This means that fluid level is below the bottom of
hydrometer. Its possible cause is excessive or
prolonged charging, a broken case, excessive tipping
or normal battery deterioration. When the battery is
found in such condition, it is possible that high
charging voltage is caused by the faulty charging
system and therefore, charging and electrical systems
need to be checked. If there is a trouble in cranking
and its cause lies in the battery, it should be replaced.