Open-Circuit Voltage Test; Load Test; Testing Open-Circuit Voltage - Jeep Wrangler 1997 Manual

TJ
DIAGNOSIS AND TESTING (Continued)
OPEN-CIRCUIT VOLTAGE TEST
A battery open-circuit voltage (no load) test will
show the state-of-charge of a battery. This test can be
used in place of the hydrometer test when a hydrom-
eter is not available, or for maintenance-free batter-
ies with non-removable cell caps .
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. D O 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. I N
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 as described in Battery Charging in this
group.
(1) Before measuring the open-circuit voltage, the sur-
face charge must be removed from the battery. Turn on
the head lamps 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 (refer to the instructions provided with the
voltmeter), measure the open-circuit voltage (Fig. 4) .
See the Open-Circuit Voltage chart. This voltage read-
ing
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 greater, it may be
load tested to reveal its cranking capacity. See Load
Test in this group for more information.
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 Bat-
tery Classifications and Ratings chart in Specifica-
tions at the back of this group.
BATTERY 8A- 7
Fig. 4 Testing Open-Circuit Voltage
898A-7
Open Circuit Voltage
Open Circuit Volts
11 .7 volts or less
12.0 volts
12.2 volts
12.4 volts
12.6 volts or more
Charge Percentage
0%
25%
50%
75%
100%
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. I N
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 as described in Battery Charging in this group.
(1) Disconnect and isolate both battery cables, negative
cable first. The battery top and posts should be clean .
(2) Connect a suitable volt-ammeter-load tester (Fig. 5)
to the battery posts (Fig. 6). Refer to the operating