Chevrolet 10 1971 Series, Chassis Service Manual

Page: 255 / 466

ENGINE-ELECTRICAL 6Y-5
CHARGING GUIDE
Recommended Rate* and Time for Fully Discharged Condition
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
^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°F.
2. Violent gassing or spewing of electrolyte occurs.
Battery is fully charged when over a two hour period at a low 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 recom­
mended.
Full charge specific gravity is 1.260-1.280 corrected for temperature with electrolyte level at split ring.
TESTING PROCEDURES
Testing procedures are used to determine whether the
Battery is (1) good and usable, (2) requires recharging
or (3) should be replaced. Analysis of Battery conditions
can be accomplished by performing a visual inspection,
Instrument Test and the full charge hydrometer test.
VISUAL INSPECTION
The first step in testing the Battery should be a visual
inspection, which very often will save time and expense in
determining Battery condition.
9 Check the outside of the Battery for a broken or
cracked case or a broken or cracked cover. If any
damage is evident, the Battery should be replaced.
• Note the electrolyte level. Levels that are too low
or too high may cause poor performance, as covered
in the section entitled "Periodic Servicing” .
• Check for loose cable connections, and for evidence
of corrosion as covered in section entitled “ Perodic
Servicing” . Correct as required before proceeding
with tests.
INSTRUMENT TEST
A number of suppliers have approved testing equipment
available. These testers have a programmed test proce­
dure consisting of a series of timed discharge and charge
events, requiring approximately 2 to 3 minutes, that will
determine the condition of the Battery with a high degree
of accuracy. When using these testers, the procedure
recommended by the tester manufacturer should be fol­
lowed. Batteries should not be charged prior to testing
or doing so may alter the test results. If a tester is not
available for testing, the "Specific Gravity Cell Com­
parison Test” may be used or an alternate method, but
with a sacrifice in testing accuracy.
NOTE:
New energizers which have become com­
pletely discharged over a relatively long period
of time, such as during vehicle storage, should
be tested by the hydrometer method. Energizers
discharged to this degree cannot be accurately
tested using equipment requiring load capability
comparison tests.
FULL CHARGE HYDROMETER TEST
This test should be used only on batteries which test
good with testing equipment or "Specific Gravity Cell
Comparison Test” but which subsequently fail in service.
• Remove the Battery from the vehicle, and adjust the
electrolyte level as necessary, by adding colorless,
odorless, drinking water.
• Fully charge the Battery at the Slow Charging
rate as covered in the section entitled “ Charging
Procedures” .
• Measure the specific gravity of the electrolyte in
each cell and interpret as follows:
Hydrometer Reading Less Than 1.230-Full charge hy­
drometer readings less than 1.230 corrected from tem­
perature indicate the Battery is defective and should
be replaced.
Hydrometer Readings Above 1.310-Full charge hydro­
meter readings above 1.310 corrected for temperature
indicate that the cells have been improperly filled (acti­
vation) or improperly serviced. Poor service and short
Battery life will result.
LOAD TEST
In addition to the instrument test and full charge hydro­
meter test, the following load test may also be performed
to check the condition of the battery.
NOTE:
Equipment to perform the test may
be procured for local suppliers of testing
equipment.
To begin, charge the battery, if necessary, until all
cells are at least 1.200 specific gravity.
1. If unable to obtain specific gravity 1.200 @ 80 °F. in
all cells, replace battery.
2. If able to obtain a specific gravity of 1.200 or more @
80°F. in all cells, remove the vent caps and connect
a 300 amp. load for 15 seconds.
10-30 CHEVROLET TRUCK SERVICE MANUAL