Chrysler 300/300 Touring/300C, Dodge Magnum. Manual - part 406

DIAGNOSIS AND TESTING

BATTERY

The battery must be completely charged and the terminals should be properly cleaned and inspected before diag-
nostic procedures are performed. (Refer to 8 - ELECTRICAL/BATTERY SYSTEM - CLEANING) and (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM - INSPECTION) for the proper battery cleaning and inspection procedures. (Refer
to 8 - ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - BATTERY CHARGING) for the
proper battery charging procedures.

MICRO 420 BATTERY TESTER

The Micro 420 automotive battery tester is designed to help the dealership technicians diagnose the cause of an
inoperative battery. (Refer to 8 - ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - USING
MICRO 420 BATTERY TESTER) for instructions on the use of the Micro 420 battery tester.

WARNING: IF THE BATTERY SHOWS SIGNS OF FREEZING, LEAKING OR LOOSE POSTS, DO NOT TEST,
ASSIST-BOOST, OR CHARGE. THE BATTERY MAY ARC INTERNALLY AND EXPLODE. PERSONAL INJURY
AND/OR VEHICLE DAMAGE MAY RESULT.

WARNING: EXPLOSIVE HYDROGEN GAS FORMS IN AND AROUND THE BATTERY. DO NOT SMOKE, USE
FLAME, OR CREATE SPARKS NEAR THE BATTERY. PERSONAL INJURY AND/OR VEHICLE DAMAGE MAY
RESULT.

WARNING: THE BATTERY CONTAINS SULFURIC ACID, WHICH IS POISONOUS AND CAUSTIC. AVOID CON-
TACT WITH THE SKIN, EYES, OR CLOTHING. IN THE EVENT OF CONTACT, FLUSH WITH WATER AND CALL
A PHYSICIAN IMMEDIATELY. KEEP OUT OF THE REACH OF CHILDREN.

A battery that will not accept a charge is inoperative, and must be replaced. Further testing is not required. A fully-
charged battery must be load tested to determine its cranking capacity. A battery that is fully-charged, but does not
pass the load test, is inoperative and must be replaced.

NOTE: Completely discharged batteries may take several hours to accept a charge. Refer to Standard Pro-
cedures for the proper battery charging procedures.

STANDARD PROCEDURE

BATTERY CHARGING

Battery charging is the means by which the battery can be restored to its full voltage potential. A battery is fully-
charged when:

•

Micro 420 electrical system tester indicates battery is OK.

•

All of the battery cells are gassing freely during battery charging.

•

Open-circuit voltage of the battery is 12.65 volts or above.

WARNING: NEVER EXCEED TWENTY AMPERES WHEN CHARGING A COLD (-1° C [30° F] OR LOWER) BAT-
TERY. THE BATTERY MAY ARC INTERNALLY AND EXPLODE. PERSONAL INJURY AND/OR VEHICLE DAM-
AGE MAY RESULT.

WARNING: IF THE BATTERY SHOWS SIGNS OF FREEZING, LEAKING, LOOSE POSTS, DO NOT TEST,
ASSIST-BOOST, OR CHARGE. THE BATTERY MAY ARC INTERNALLY AND EXPLODE. PERSONAL INJURY
AND/OR VEHICLE DAMAGE MAY RESULT.

WARNING: EXPLOSIVE HYDROGEN GAS FORMS IN AND AROUND THE BATTERY. DO NOT SMOKE, USE
FLAME, OR CREATE SPARKS NEAR THE BATTERY. PERSONAL INJURY AND/OR VEHICLE DAMAGE MAY
RESULT.

8F - 10

BATTERY SYSTEM

WARNING: IF THE BATTERY IS EQUIPPED WITH REMOVABLE CELL CAPS, BE CERTAIN THAT EACH OF
THE CELL CAPS IS IN PLACE AND TIGHT BEFORE THE BATTERY IS RETURNED TO SERVICE. PERSONAL
INJURY AND/OR VEHICLE DAMAGE MAY RESULT FROM LOOSE OR MISSING CELL CAPS.

CAUTION: Always disconnect and isolate the battery negative cable before charging a battery. Do not
exceed sixteen volts while charging a battery. Damage to the vehicle electrical system components may
result.

CAUTION: Battery electrolyte will bubble inside the battery case during normal battery charging. Electrolyte
boiling or being discharged from the battery vents indicates a battery overcharging condition. Immediately
reduce the charging rate or turn off the charger to evaluate the battery condition. Damage to the battery
may result from overcharging.

CAUTION: The battery should not be hot to the touch. If the battery feels hot to the touch, turn off the
charger and let the battery cool before continuing the charging operation. Damage to the battery may result.

After the battery has been charged to 12.65 volts or greater, perform a load test to determine the battery cranking
capacity, (Refer to 8 - ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - USING MICRO
420 BATTERY TESTER) for the proper battery load test procedures. If the battery will endure a load test, return the
battery to service. If the battery will not endure a load test, it is inoperative and must be replaced.

Clean and inspect the battery hold downs, tray, terminals, posts, and top before completing battery service. (Refer
to 8 - ELECTRICAL/BATTERY SYSTEM - CLEANING) and (Refer to 8 - ELECTRICAL/BATTERY SYSTEM -
INSPECTION) for the proper battery system cleaning and inspection procedures.

CHARGING A COMPLETELY DISCHARGED BATTERY

The following procedure should be used to recharge a completely discharged battery. Unless this procedure is prop-
erly followed, a good battery may be needlessly replaced.

1. Measure the voltage at the battery posts with a voltmeter, accurate to 1/10 (0.10) volt. If the reading is below ten

volts, the battery charging current will be low. It could take some time before the battery accepts a current
greater than a few milliamperes. Such low current may not be detectable on the ammeters built into many battery
chargers.

2. Disconnect and isolate the battery negative cable. Connect the battery charger leads. Some battery chargers are

equipped with polarity-sensing circuitry. This circuitry protects the battery charger and the battery from being
damaged if they are improperly connected. If the battery state-of-charge is too low for the polarity-sensing cir-
cuitry to detect, the battery charger will not operate. This makes it appear that the battery will not accept charg-
ing current. See the instructions provided by the manufacturer of the battery charger for details on how to bypass
the polarity-sensing circuitry.

3. Battery chargers vary in the amount of voltage and current they provide. The amount of time required for a bat-

tery to accept measurable charging current at various voltages is shown in the Charge Rate Table. If the charg-
ing current is still not measurable at the end of the charging time, the battery is inoperative and must be
replaced. If the charging current is measurable during the charging time, the battery may be good and the charg-
ing should be completed in the normal manner.

CHARGE RATE TABLE

Voltage

Hours

16.0 volts maximum

up to 4 hours

14.0 to 15.9 volts

up to 8 hours

13.9 volts or less

up to 16 hours

BATTERY SYSTEM

8F - 11

CHARGING TIME REQUIRED

The time required to charge a battery will vary, depending upon the following factors:

•

Battery Capacity - A completely discharged heavy-duty battery requires twice the charging time of a small
capacity battery.

•

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 battery charger is connected to a cold battery, the current accepted by the battery will be very low at
first. As the battery warms, it will accept a higher charging current rate (amperage).

•

Charger Capacity - A battery charger that supplies only five amperes will require a longer charging time. A
battery charger that supplies twenty amperes or more will require a shorter charging time.

•

State-Of-Charge - A completely discharged battery requires more charging time than a partially discharged
battery. Electrolyte is nearly pure water in a completely discharged battery. At first, the charging current
(amperage) will be low. As the battery charges, the specific gravity of the electrolyte will gradually rise.

The Battery Charging Time Table gives an indication of the time required to charge a typical battery at room tem-
perature based upon the battery state-of-charge and the charger capacity.

BATTERY CHARGING TIME TABLE

Charging

Amperage

5 Amps

Amps

20 Amps

Open Circuit

Voltage

Hours Charging @ 21° C (70° F)

12.25 to 12.49

6 hours

3 hours

1.5

hours

12.00 to 12.24

10 hours

5 hours

2.5

hours

10.00 to 11.99

14 hours

7 hours

3.5

hours

Below 10.00

18 hours

9 hours

4.5

hours

USING MICRO 420 BATTERY TESTER

Always use the Micro 420 Instruction Manual that was
supplied with the tester as a reference. If the Instruc-
tion Manual is not available the following procedure
can be used:

WARNING: ALWAYS WEAR APPROPRIATE EYE
PROTECTION

AND

USE

EXTREME

CAUTION

WHEN WORKING WITH BATTERIES.

8F - 12

BATTERY SYSTEM

BATTERY TESTING

1. If testing the battery OUT-OF-VEHICLE, clean the battery terminals with a wire brush before testing, (Refer to 8

- ELECTRICAL/BATTERY SYSTEM - CLEANING).

2. If testing the battery IN-THE-VEHICLE, make certain all of the vehicle accessory loads are OFF, including the

ignition. The preferred test position is at the battery terminals. If the battery is not accessible, you may test
using both the positive and negative jumper posts. Select TESTING AT JUMPER POST when connecting to that
location.

3. Connect the tester to the battery or jumper posts, the red clamp to positive (+) and the black clamp to negative

(–).

NOTE: Multiple batteries connected in parallel must have the ground cable disconnected to perform a bat-
tery test. Failure to disconnect may result in false battery test readings.

4. Using the ARROW key select in or out of vehicle testing and press ENTER to make a selection.

5. If not selected, choose the Cold Cranking Amp (CCA) battery rating. Or select the appropriate battery rating for

your area (see menu). The tester will then run its self programmed test of the battery and display the results.
Refer to the test result table noted below.

CAUTION: If REPLACE BATTERY is the result of the test, this may mean a poor connection between the
vehicle’s cables and battery exists. After disconnecting the vehicle’s battery cables from the battery, retest
the battery using the OUT-OF-VEHICLE test before replacing.

6. While viewing the battery test result, press the CODE button and the tester will prompt you for the last 4 digits

of the VIN. Use the UP/DOWN arrow buttons to scroll to the correct character; then press ENTER to select and
move to the next digit. Then press the ENTER button to view the SERVICE CODE. Pressing the CODE button
a second time will return you to the test results.

BATTERY TEST RESULTS

GOOD BATTERY

Return to service

GOOD - RECHARGE

Fully charge battery and return to service

CHARGE & RETEST

Fully charge battery and retest battery

REPLACE BATTERY

Replace the battery and retest complete system

BAD-CELL REPLACE

Replace the battery and retest complete system

NOTE: The SERVICE CODE is required on every warranty claim submitted for battery replacement.

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 in place of the hydrometer test when a hydrometer is not available, or for maintenance-free batteries with
non-removable cell caps.

Before proceeding with this test, completely charge the battery, (Refer to 8 - ELECTRICAL/BATTERY SYSTEM/
BATTERY - STANDARD PROCEDURE - BATTERY CHARGING).

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, negative cable first.

BATTERY SYSTEM

8F - 13

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