Chevrolet 70 1969 Series, Shop Manual

Page: 374 / 913

ENGINE ELECTRICAL 6Y-3
(corrected to 80°F.) or if there is a variation of
more than 25 gravity points between cells after
thorough slow charging, replace the battery.
F A S T CH AR G IN G
The Fast Charge method supplies current to
the battery at a 40 to 50 ampere rate for a 1-A
hour period of time. If the electrolyte temperature
CHARGING GUIDE FOR BATTERIES
Below is a suggested list of battery charging
rates. Refer to applicable chart.
C H A R T 1: For dry charged batteries being ac­
tivated with electrolyte at a temper­
ature under 60°F., or with batteries
which are expected to go into immed­
iate operation in below freezing wea­
ther.
Amp-Hour
Capacity
Dry Battery
Warm-up Charge
100
or
Less
10 Min.
15 Amps
Over
100
10 Min.
30 Amps
C H A R T 2: For batteries which require a boost
charge for the "Light Load Test”
___________ procedures.________________________
Amp-Hour
Capacity
Light Load Test
Boost Charge
100
or
Less
20 Min.
50 Amps
Over
100
30 Min.
60 Amps
C HAR T 3: For batteries which have become
discharged and require charging. It
should be recognized that slow charg­
ing is the best and only method of
completely recharging batteries. How­
ever, since time is often of import­
ance, two other methods are offered
for partial battery re-charges listed
in this chart.
Amp-Hour
Capacity
Slow
Charging
Fast
Charging
Emergency
Boost Charging
100
or
Less
24 Hours
1-1/2 Hrs. 30 Minutes
4 Amps 40 to
50 Amps
40 to 50 Amps
Over
100
24 Hours 3 Hours 1-1/2 Hours
9 Amps 40 to
50 Amos
40 to 50 Amps
reaches 125°F., before the l-l A hour period is
completed, the battery must be taken off charge
temporarily, or the charging rate reduced to avoid
damage to the battery.
Although a battery cannot be brought to a fully
charged condition during Fast Charge, it can be
substantially recharged or "boosted." In order to
bring the battery to a fully charged condition, the
charging cycle must be finished by the Slow Charge
method.
E M E R G E N C Y B O O S T C H A R G IN G
In cases where the battery is not sufficiently
charged to crank the engine, an emergency boost
charge may be applied as a temporary expedient
in order to crank the engine. The Emergency Boost
Charge method consists of charging at a 40 to 50
ampere rate for a period of one-half hour.
It should be particularly noted that the E m e r ­
gency -Boost Charge method will not necessarily
restore the battery to a useful state of charge for
continued service. After an Emergency Boost
Charge failure to charge the battery further, either
by a long uninterrupted driving period or by the
Fast Charge or Slow Charge method, may result
in failure to crank the engine the next time crank­
ing is attempted. A battery should never be con­
demned on the basis of failure to crank the engine
after an emergency boost charge. Although an
emergency boost charge may put enough energy
into the battery to crank the engine once, further
charging usually is necessary in order to create
a sufficient reserve to crank a second or third
time. Refer to "Charging Guide For Batteries"
previously on this page.
BATTERY TESTS
Testing procedures are used to determine
whether the battery is (1) good and usable, (2) re­
quires recharging, or (3) should be replaced. Anal­
ysis of battery conditions can be accomplished by
performing a visual inspection, Instrument Test,
Full Charge Hydrometer Test, and the Light Load
Test.
IM P O R T A N T : Do not attempt to perform the
Light Load Test on vehicles equipped with batteries
having a one-piece cover (fig. 1).
V ISU A L IN S P E C T IO N
The first step in testing the battery should be
a visual inspection, which very often will save
time and expense in determining battery condition.
1. Check the outside of the battery for abroken
or cracked case or a broken or cracked cover. If
any damage is evident, the battery should be re­
placed.
2. Note the electrolyte level. Levels that are
too low or too high may cause poor performance.
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH OP M A N U A L