Pontiac Fiero 1988 Service Manual page 388

BATTERY 6D1-3
ESTIMATED MINIMUM
TEMPERATURE VOLTAGE
7 0 ° F . ( 2 1 ° C . ) 9 . 6
5 0 ° F . ( 1 0 ° C . ) 9 . 4
30° F. ( 0 ° C . ) 9.1
15° F.
( - 1 0 ° C . ) •
8.8
0 ° F . ( - 1 8 ° C . ) 8 . 5
0 ° F . ( B E L O W : - 1 8 ° C . ) 8 . 0
520011 6 P
Fig. 3 Minimum Voltage
1. Do not charge battery if hydrometer is clear or
light yellow. Replace battery.
2. If the battery feels hot 5 2 ° C (125°F), or if violent
gassing or spewing of electrolyte through the vent
holes occurs, discontinue charging or reduce
charging rate.
Charging Procedure
1. Batteries with green dot showing do not require
charging unless they have just been discharged
(such as in cranking vehicle).
2. When charging sealed-terminal batteries out of
vehicle, install adapter kit (AC Delco part
number ST-1201 or GM part number 1846855, or
equivalent). (Refer to Fig. 2.) Post-type batteries
need no adapters.
3. Make sure all charger connections are clean and
tight.
4. For best results, batteries should be charged while
electrolyte and plates are at room temperature. A
battery that is extremely cold may not accept
current for several hours after starting charger.
5. Charge battery until green dot appears (see
"Charging Time Required"). Battery should be
checked every half-hour while charging. Tipping
or shaking battery may be necessary to make
green dot appear.
6. After charging, battery should be load tested as
outlined in BATTERY DIAGNOSIS.
Charging Time Required:
The time required to charge a battery will vary
depending upon the following factors:
• Size of Battery
- A completely discharged
large heavy-duty battery requires more than
twice the recharging as a completely discharged
small passenger car battery.
• Temperature
- A longer time will be needed to
charge any battery at 0°F than at 80°F. When a
fast charger is connected to a cold battery, the
current accepted by the battery will be very low
at first. Then, in time, the battery will accept a
higher rate as the battery warms.
• Charger Capacity
- A charger which can
supply only five amperes will require a much
longer period of charging than a charger that can
supply 30 amperes or more.
•
State=Of-Charge
- A completely discharged
battery requires more than twice as much charge
as a one-half charged battery. Because the
electrolyte is nearly pure water and a poor
conductor in a completely discharged battery, the
current accepted by the battery is very low at
first. Later, as the charging current causes the
electrolyte acid content to increase, the charging
current will likewise increase.
CHARGING A COMPLETELY DISCHARGED
BATTERY (OFF THE VEHICLE)
The following procedure should be used to
recharge a completely discharged battery:
Unless the procedure is properly followed, a
perfectly good battery may be needlessly replaced.
1. Measure voltage at battery terminals with an
accurate voltmeter. If below 10 volts, the charge
current will be very low and it could take some
time before it accepts current in excess of a few
milliamperes.
Such low current may not be detectable on
ammeters available in the field.
2. Set battery charger on high setting.
3. Some chargers feature polarity protection
circuitry, which prevents charging unless the
charger leads are connected to the battery
terminals correctly. A completely discharged
battery may not have enough voltage to activate
this circuitry, even though leads are connected
properly, making it appear that the battery will
not accept charging current. Therefore, follow
the specific charger manufacturer's instruction
telling how to bypass or override the circuitry so
that the charger will turn on and charge a
low-voltage battery.
4. Battery chargers vary in the amount of voltage
and current they provide. The time required for
the battery to accept measurable charger current
at various voltages may be as follows:
B A T T E R Y T O P B A T T E R Y T O P B A T T E R Y T O P
D A R K E N E D
I N D I C A T O R
( W I T H G R E E N
D O T )
M A Y B E J U M P
S T A R T E D
D A R K E N E D
I N D I C A T O R
( N O G R E E N
D O T )
M A Y B E J U M P
S T A R T E D
L I G H T
Y E L L O W O R
B R I G H T
I N D I C A T O R
D O N O T J U M P
S T A R T
520012-6P
Fig. 4 Built-in Hydrometer