Dodge RAM TRUCK 1500 1995 Service Manual page 341

81 - 8 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS
BATTERY CHARGING
A battery is fully-charged when:
© all cells are gassing freely during charging
© a green color is visible in sight glass of built-in
test indicator
© three corrected specific gravity tests, taken at
1-hour intervals, indicate no increase in specific grav­
ity
• open circuit voltage is 12.4 volts or above.
WARNING: DO NOT A S S I S T BOOST OR C H A R G E A
BATTERY THAT HAS LOW ELECTROLYTE L E V E L
OR IS F R O Z E N . BATTERY MAY A R C INTERNALLY
AND E X P L O D E ,
WARNING: E X P L O S I V E HYDROGEN G A S F O R M S IN
AND AROUND BATTERY* DO NOT SMOKE, USE
FLAME, OR CREATE S P A R K S NEAR BATTERY.
WARNING: POISONOUS AND CAUSTIC. BATTERY
CONTAINS S U L F U R I C ACID. AVOID CONTACT WITH
SKIN, E Y E S , OR CLOTHING. IN EVENT OF CON­
TACT, F L U S H WITH WATER AND CALL PHYSICIAN
IMMEDIATELY. K E E P OUT OF REACH OF CHIL­
DREN.
CAUTION: Always disconnect the battery negative
cable before charging battery to avoid damage to
electrical system components. Do not exceed 16.0
volts while charging battery.
Models equipped with the diesel engine op­
tion are equipped with two 12-volt batteries
connected in parallel (positive-to-positive/nega­
tive-to-negative). The secondary battery on the
passenger side is dedicated to providing cur­
rent for the operation of the intake manifold
air heater. The primary battery on the driver's
side is dedicated to all other vehicle electrical
requirements. In order to ensure proper charg­
ing of each battery, these batteries MUST be
disconnected from each other as well as from
the vehicle electrical system while being
charged.
Battery electrolyte will bubble inside battery case
during normal battery charging. If the electrolyte
boils, or is discharged from the vent holes while
charging, immediately reduce charging rate or turn
OFF charger and evaluate battery condition.
Battery should not be hot to the touch. If the
battery feels hot to the touch, turn OFF
charger and let battery cool before continuing
charging operation.
Some battery chargers are equipped with polarity
sensing circuitry. This circuitry protects the charger
and/or battery from being damaged if improperly con­
nected.
If the battery state-of-charge is too low for the po­
larity sensing circuitry to detect, the charger will not
operate. This makes it appear that the battery will
not accept charging current. Refer to instructions
provided with the battery charger being used to by­
pass the polarity sensing circuitry.
BATTERY CHARGING TIME TABLE
Charging Amperage
5 Amps
10 Amps 20 Amps
Open
Circuit Voltage H@urs Charging at 21°C
12.25 to 12.39
6Hrs. 3Hrs. 1.5 Hr.
12.00
to
12.24 8Hrs.
4Hrs. 2Hrs.
11.95 to 12.09
12Hrs. 6Hrs. 3 Hrs. 1
10.00 to 11.95
14Hrs. 7Hrs. 3.5 H
s. |
10.00 to 0 See Charging Completely
Discharged Battery
928A-19
After the battery has been charged to 12.4 volts or
greater, perform a load test to determine cranking
capacity. If the battery will endure a load test, return
the battery to use. If the battery will not endure a
load test, it must be replaced.
Clean and inspect battery holddowns, tray, termi­
nals, posts, and top before completing service. Refer
to Group 8B - Battery/Starter/Generator Service for
more information.
emMmmiNG t i m e REQUIRED
The time required to charge a battery will vary, de­
pending upon the following factors:
(1) Battery Capacity - A completely discharged
heavy-duty battery requires twice the recharging
time of a small capacity battery.
WARNING: NEVER E X C E E D 20 A M P S W H E N
CHARGING A COLD (-1°C*30°F) BATTERY. PER­
SONAL INJURY MM RESULT.
(2) Temperature - A longer time will be needed to
charge a battery at -18°C (0°F) than at 27°C (80°F).
When a fast charger is connected to a cold battery,
current accepted by the battery will be very low at
first. As the battery warms, it will accept a higher
charging current rate.
(3) Charger Capacity - A charger that supplies
only 5 amperes will require a longer charging time. A
charger that supplies 20 amperes or more requires a
shorter charging time.
(4) State-Of-Charge - A completely discharged
battery requires more charging time than a partially
discharged battery. Electrolyte i s nearly pure water
in a completely discharged battery. At first, the