Pontiac Fiero 1988 Service Manual page 386

BATTERY 6D1-1
SECTION 6D1
B A T T E R Y
CONTENTS
G e n e r a l D e s c r i p t i o n ......
Battery
Ratings
Reserve Capacity .............
Cold Cranking Amperage
Built-in Hydrometer .......
D i a g n o s i s
S e r v i c e P r o c e d u r e s .......
6D1-1 Battery Charging 6D1-2
6D1-1 Charging Completely Discharged
6D1-1 Battery 6D1-3
6D1-1 Jump Starting 6D1-4
O n - C a r S e r v i c e
6D1-5
JJJJ'J
Battery Cable Routing 6D1-6
2£r2
Specifications 6D1-7
GENERAL DESCRIPTION
The engine electrical system includes the battery,
ignition (primary and secondary), starter (and related
wiring) and the generator (and related wiring).
Diagnostic charts (see Section 6D) will aid in
trouble-shooting system faults. When a fault is traced
to a particular component, refer to that components'
section of the service manual.
BATTERY
The sealed battery (see Fig. 1) is standard on all
cars. (See Specifications for specific applications.)
There are no vent plugs in the cover. The battery is
completely sealed, except for two small vent holes in
the sides. These vent holes allow the small amount of
gas produced in the battery to escape. The battery has
the following advantages over conventional batteries:
1. No water addition for the life of the battery.
2. Overcharge protection. If too much voltage is
applied to the battery, it will not accept as much
current as a conventional battery. In a
conventional battery, the excess voltage will still
try to charge the battery, leading to gassing which
causes liquid loss.
3. Not as liable to self-discharge as compared to a
conventional battery. This is particularly
important when a battery is left standing for long
periods of time.
4. More power available in a lighter and smaller
case.
The battery has three major functions in the
electrical system: First, it provides a source of energy
for cranking the engine; Second, it acts as a voltage
stabilizer for the electrical system; And third, it can, for
a limited time, provide energy when the electrical load
used exceeds the output of the generator.
Ratings
A battery has two ratings: (1) a reserve capacity
rating at 2 7 ° C (80°F) which is the time a fully charged
battery will provide 25 amperes current flow at or
above 10.5 volts; and (2) a cold rating at - 1 8°C (0°F)
which indicates the cranking load capacity (see
Diagnosis Section for specific battery ratings).
BUILT-IN
HYDROMETER
H2Q229-6D
Fig. 1 Sealed Battery
Reserve Capacity
The "Reserve Capacity" is the maximum length
of time it is possible to travel at night with minimum
electrical load and no generator output.
Expressed in minutes it is the time required for
a fully charged battery, at a temperature of 8 0 ° F being
discharged at a constant current of 25-amperes, to
reach a terminal voltage of 10.5 volts.
Cold Cranking Amperage
The "Cold Cranking Amperage" test is expressed
at a battery temperature of 0°F. The current rating is
the minimum amperage, which must be maintained by
the battery for 30 seconds at the specified temperature,
while meeting a minimum voltage requirement of 7.2
volts. This rating is a measure of cold cranking
capacity.
The battery is not designed to last indefinitely;
however, with proper care, it will provide many years
of service.
If the battery tests good, but fails to perform
satisfactorily in service for no apparent reason, the
following are some of the more important factors that
may point to the cause of trouble:
1. Vehicle accessories left on overnight.
2. Slow average driving speeds for short periods.