GMC 1976 ZEO 6083 Maintenance Manual page 393

RECOMMENDED RATE* AND TIME FOR FULLY DISCHARGED CONDITION
CAUTION : EXERCISE CAkE WHEN ATTACHING CHARGER LEADS TO SIDE TERMINAL STUDS
TO AVOID
CONTACT WITH VEHICLE METAL COMPONENTS WHICH COULD RESULT IN DAMAGE TO THE ENERGIZER
.
* Initial rate for constant voltage taper rate charger .
To avoid damage, charging rate must be reduced or temporarily halted if :
1 . Electrolyte temperature exceeds 125 0F .
2 . Violent gassing or spewing of electrolyte occurs.
Battery is fully charged when over a two hour period at a lo- , charging rate in amperes all cells are gassing freely and no
change in specific gravity occurs . For the most satisfactory charging, the lower charging rates in amperes are recommended .
Full charge specific gravity is 1 .260-1 .280 corrected for temperature with electrolyte level at split ring .
4. Maintain the storage area at 60°F. (15.6°C.), or
higher to aid activation .
A wet charged battery will not maintain its
charged condition during storage, and must be re-
charged periodically . During storage, even though
the battery is not in use, a slow reaction takes place
between the chemicals inside the battery which
causes the battery to lose charge and "wear out"
slowly . This reaction is called "self-discharge ." The
rate at which self-discharge occurs varies directly
with the temperature of the electrolyte .
Note that an battery stored in an area at 100°F.
(37 .8°C .) for 60 days has a much lower specific
gravity and consequently a lower state of charge than
one stored in an area at 60°F . (15.6°C .) for the same
length of time .
To minimize self-discharge, a wet battery should
be stored in as cool a place as possible, provided the
electrolyte does not freeze .
A wet battery which has been allowed to stand
idle for a long period of time without recharging may
become so badly damaged by the growth of lead
sulfate crystals (sulfation) in the plates that it can
never be restored to a normal charged condition. An
battery in this condition not only loses its capacity
but also is subject to changes in its charging charac-
teristics. These changes, due to self-discharge, are
often serious enough to prevent satisfactory perform-
ance in a vehicle.
Periodic recharging, therefore, is necessary to
maintain a wet charged battery in a satisfactory con-
dition while in storage. See paragraph "Charging
Wet battery in Storage ."
Charging Wet Battery in Storage
ENGINE ELECTRICAL
6Y- 1 3
Before placing a battery on charge, always check
the electrolyte level and add water, as necessary, to
bring the electrolyte up to the bottom of the split
vent .
The battery should be brought to a fully charged
condition every 30 days by charging as covered un-
der heading of "Battery Charging Procedures".
Trickle charging should not be used to maintain
on battery in a charged condition when in storage .
The low charge rate method applied every 30 days is
the best method of maintaining a wet charged battery
in a fully charged condition without damage .
Electrolyte Freezing
The freezing point of electrolyte depends on its
specific gravity. The following table gives the freez-
ing temperatures of electrolyte at various specific
gravities.
Value of
Value of
Specific
Specific
Gravity Freezing
Gravity Freezing
Corrected Temp .
Corrected Temp .
to 80°F . Deg. F.
to 80°F. Deg. F.
(26.7°C .) (Deg . C.)
(26.7°C .) (Deg . C.)
1 .100 18 (-7.8) 1 .220 -13(-25)
1 .120 13 (-10 .6) 1 .240 -50(-45 .6)
1 .140 8 (-13 .3) 1 .260 -75 (-60)
1 .160 1 (-17 .2) 1 .280 -92 (-68 .9)
1 .180 -6 (-21 .1) 1 .300 -95 (-70 .6)
1 .200
-17 (-27 .2)
Watt Rating
5 Amperes 10 Amperes
20 Amperes 30 Amperes
40 Amperes 50 Amperes
Below 2450
10 Hours 5 Hours 2-1/2 Hours
2 Hours
2450-2950 12 Hours
6 Hours 3 Hours
2 Hours 1-1/2 Hours
Above 2950 15 Hours
7-1/2 Hours 3-1/4 Hours
2 Hours 1-3/4 Hours 1-1/2 Hours