Chrysler RAM TRUCK 2500 1994 Service Manual page 318

ELECTRICAL 8A - 3
BATTERY TEST PROCEDURES
INDEX
page
Battery Charging
6
Battery Load Test 5
Battery Open Circuit Voltage Test 5
General Information
3
page
Ignition-Off Draw (IOD) Diagnosis
. . 4
State-Of-Charge Test Using Test Indicator 3
Test Indicator 3
GENERAL INFORMATION
The battery stores, stabilizes, and produces electri­
cal current. A battery must be able to accept a charge
and produce high-amperage current over an extended
period. A chemical reaction takes place between sul­
furic acid solution (electrolyte) and lead positive/neg­
ative plates i n each cell of the battery. As the battery
discharges, the plates collect acid from the electro­
lyte. When the charging system charges the battery,
water is converted to sulfuric acid i n the battery. A
factory installed battery has a built-in test indicator
to help determine state-of-charge. The factory in­
stalled battery is also nonrefillable, water can not be
added. The battery is vented to release excess gases
that are created when the battery is being charged or
discharged. The battery top, posts, and terminals
should be cleaned when other underhood mainte­
nance is performed (Fig. 3).
WARNING: DO NOT ATTEMPT TO A S S I S T BOOST,
C H A R G E , OR T E S T BATTERY WHEN E L E C T R O ­
LYTE L E V E L IS B E L O W T H E T O P O F T H E P L A T E S
( Y E L L O W OR BRIGHT C O L O R IS V I S I B L E IN T E S T
INDICATOR). P E R S O N A L INJURY MAY O C C U R .
Fig. 3 Battery Construction and Test Indicator
When the electrolyte level is below the top of the
plates (yellow or bright test indicator), the battery
must be replaced. The battery must be completely
charged (green test indicator) and the top, posts, and
terminals should be properly cleaned before diagnos­
tic procedures are performed. Refer to Group 8B -
Battery/Starter/Generator Service, for additional in­
formation.
TEST INDICATOR
A test indicator (hydrometer) built into the top of
the battery case, provides visual information for bat­
tery testing (Fig. 4). I t is important when using test
indicator that the battery be level and have a clean
top to see correct indications. Additional light may be
required to view indicator.
WARNING: DO NOT U S E O P E N F L A M E . E X P L O S I V E
G A S E S FORM A B O V E BATTERY.
Fig. 4 Built-in Test Indicator
STATE-OF-CHARGE TEST USING TEST INDICATOR
The built-in test indicator (hydrometer) measures
the specific gravity of the electrolyte. Specific gravity
(SG) will indicate state-of-charge (voltage); although,
the test indicator will not indicate cranking capacity
of the battery. Refer to Battery Load Test for more
information. Look into the sight glass and note the
color of the indicator (Fig. 5), refer to the following
description as color indicates:
G R E E N - 7 5 to 100% state-of-charge
The battery is adequately charged for further test­
ing or return to use. I f the vehicle will not crank for
a maximum 15 seconds, refer to Battery Load Test
for more information.
B L A C K OR DARK—0 to 7 5 % state-of-charge
The battery is inadequately charged and must be
charged until green indicator is visible (12.4 volts or