Standard Procedure - Open-Circuit Voltage Test; Standard Procedure - Ignition-Off Draw Test - Chrysler Dodge Caravan 2002 Manual

RS
BATTERY (Continued)
CONVENTIONAL BATTERY CHARGING TIME TABLE
Charging
Amperage
Open Circuit
Voltage
12.25 to 12.49
12.00 to 12.24 10 hours
10.00 to 11.99 14 hours
Below 10.00 18 hours
STANDARD PROCEDURE - OPEN-CIRCUIT
VOLTAGE TEST
A battery open-circuit voltage (no load) test will
show the approximate state-of-charge of a battery.
This test can be used if no other battery tester is
available.
Before proceeding with this test, completely charge
the battery. Refer to Standard Procedures for the
proper battery charging procedures.
(1) Before measuring the open-circuit voltage, the
surface charge must be removed from the battery.
Turn on the headlamps for fifteen seconds, then
allow up to five minutes for the battery voltage to
stabilize.
(2) Disconnect and isolate both battery cables, neg-
ative cable first.
(3) Using a voltmeter connected to the battery
posts (see the instructions provided by the manufac-
turer of the voltmeter), measure the open-circuit volt-
age (Fig. 9).
Fig. 9 Testing Open-Circuit Voltage - Typical
See the Open-Circuit Voltage Table. This voltage
reading will indicate the battery state-of-charge, but
will not reveal its cranking capacity. If a battery has
an open-circuit voltage reading of 12.4 volts or
10
5 Amps 20 Amps
Amps
Hours Charging @ 21° C (70°
F)
6 hours 3 hours
5 hours
7 hours
9 hours
greater, it may be load tested to reveal its cranking
capacity. Refer to Standard Procedures for the proper
battery load test procedures.
OPEN CIRCUIT VOLTAGE TABLE
Open Circuit Voltage
1.5
11.7 volts or less
hours
12.0 volts
2.5
hours 12.2 volts
3.5 12.45 volts
hours
12.65 volts or more
4.5
STANDARD PROCEDURE - IGNITION-OFF
hours
DRAW TEST
The term Ignition-Off Draw (IOD) identifies a nor-
mal condition where power is being drained from the
battery with the ignition switch in the Off position. A
normal vehicle electrical system will draw from five
to thirty-five milliamperes (0.015 to 0.025 ampere)
with the ignition switch in the Off position, and all
non-ignition controlled circuits in proper working
order. Up to twenty-five milliamperes are needed to
enable the memory functions for the Powertrain Con-
trol Module (PCM), digital clock, electronically tuned
radio, and other modules which may vary with the
vehicle equipment.
A vehicle that has not been operated for approxi-
mately twenty-one days, may discharge the battery
to an inadequate level. When a vehicle will not be
used for twenty-one days or more (stored), remove
the IOD fuse from the Integrated Power Module
(IPM). This will reduce battery discharging.
Excessive IOD can be caused by:
• Electrical items left on.
• Faulty or improperly adjusted switches.
• Faulty or shorted electronic modules and compo-
nents.
• An internally shorted generator.
• Intermittent shorts in the wiring.
If the IOD is over twenty-five milliamperes, the
problem must be found and corrected before replac-
ing a battery. In most cases, the battery can be
charged and returned to service after the excessive
IOD condition has been corrected.
(1) Verify that all electrical accessories are off.
Turn off all lamps, remove the ignition key, and close
all doors. If the vehicle is equipped with an illumi-
nated entry system or an electronically tuned radio,
allow the electronic timer function of these systems
to automatically shut off (time out). This may take
up to three minutes.
(2) Disconnect the battery negative cable.
(3) Set an electronic digital multi-meter to its
highest amperage scale. Connect the multi-meter
BATTERY SYSTEM
Charge Percentage
0%
25%
50%
75%
100%
8F - 13