Jeep Cherokee 2000 Service Manual - page 309
LOAD TEST
A battery load test will verify the battery cranking
capacity. The test is based on the Cold Cranking
Amperage (CCA) rating of the battery. See the label
affixed to the battery case, or refer to Battery in the
index of this service manual for the location of the
proper
factory-installed
battery
specifications
to
determine the battery CCA rating.
WARNING:
•
IF THE BATTERY SHOWS SIGNS OF FREEZ-
ING, LEAKING, LOOSE POSTS, OR LOW ELECTRO-
LYTE LEVEL, DO NOT TEST, ASSIST-BOOST, OR
CHARGE. THE BATTERY MAY ARC INTERNALLY
AND EXPLODE. PERSONAL INJURY AND/OR VEHI-
CLE DAMAGE MAY RESULT.
•
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.
•
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.
•
IF THE BATTERY IS EQUIPPED WITH REMOV-
ABLE CELL CAPS, BE CERTAIN THAT EACH OF
THE CELL CAPS IS IN PLACE AND TIGHT BEFORE
THE BATTERY IS RETURNED TO SERVICE. PER-
SONAL INJURY AND/OR VEHICLE DAMAGE MAY
RESULT FROM LOOSE OR MISSING CELL CAPS.
Before proceeding with this test, completely charge
the battery. Refer to Battery Charging in the index
of this service manual for the location of the proper
battery charging procedures.
(1) Disconnect and isolate both battery cables, neg-
ative cable first. The battery top and posts should be
clean.
(2) Connect a suitable volt-ammeter-load tester
(Fig. 10) to the battery posts (Fig. 11). See the
instructions provided by the manufacturer of the
tester you are using. Check the open-circuit voltage
(no load) of the battery. Refer to Open-Circuit Volt-
age Test in this section for the proper battery open-
circuit voltage test procedures. The battery open-
circuit voltage must be 12.4 volts or greater.
(3) Rotate the load control knob (carbon pile rheo-
stat) to apply a 300 ampere load to the battery for
fifteen seconds, then return the control knob to the
Off position (Fig. 12). This will remove the surface
charge from the battery.
(4) Allow the battery to stabilize to open-circuit
voltage. It may take up to five minutes for the bat-
tery voltage to stabilize.
(5) Rotate the load control knob to maintain a load
equal to 50% of the CCA rating of the battery (Fig.
13). After fifteen seconds, record the loaded voltage
reading, then return the load control knob to the Off
position.
(6) The voltage drop will vary with the battery
temperature at the time of the load test. The battery
temperature can be estimated by using the ambient
temperature during the past several hours. If the
Open Circuit Voltage
Open Circuit Volts
Charge Percentage
11.7 volts or less
0%
12.0 volts
25%
12.2 volts
50%
12.4 volts
75%
12.6 volts or more
100%
Fig. 10 Volt-Ammeter-Load Tester - Typical
Fig. 11 Volt-Ammeter-Load Tester Connections -
Typical
1 – INDUCTION AMMETER CLAMP
2 – NEGATIVE CLAMP
3 – POSITIVE CLAMP
8A - 12
BATTERY
XJ
DIAGNOSIS AND TESTING (Continued)