Battery - Testing and Inspection
BULLETIN NUMBERSB88-04-003
ISSUE DATE
April 19, 1988
GROUP
ELECTRICAL
BATTERY TEST AND CHARGE
VEHICLES AFFECTED
All Isuzu models.
SERVICE INFORMATION
Many batteries that are replaced because of poor performance are later found (during warranty inspection) to have no defects. This Service Bulletin describes proper battery testing and charging procedures which must be completed before a battery is replaced. All technical readings must be recorded on the warranty repair order.
SERVICE PROCEDURE
WARNING
Keep battery away from open flame, as hydrogen gas generated by battery is highly flammable. Wear safety glasses when working near batteries. In case of skin contact with battery acid, flush affected area immediately with water.
CAUTION
Charge battery only when battery temperature is below 60 degrees C (140 degrees F). If battery temperature rises above this temperature, stop charging procedure.
1. Put voltmeter test leads to battery terminals.
a. If battery voltage is 12.4 V or above, load test battery as described in Step 3 of this procedure.
b. If battery voltage is under 12.4 V, fast charge battery as described in Step 2 before performing load test.
2. Determine fast charge amperage (Figure 1). Fast charge battery for 30 minutes at amperage rate no higher than specified in Figure 1. Take voltage reading after charge.
a. If voltage is above 16 V, replace battery.
b. If voltage is between 12 V and 16 V, continue charging at the same rate for an additional 3-1/2 hours.
c. Perform load test as described below.
3. Load test battery as follows. This procedure is based on the Sun VAT 40 starting/charging system tester check the manufacturer's operating instructions if using a different machine.
a. Set tester LOAD CONTROL and FUNCTION SELECTOR knobs to OFF.
b. Connect red clamp of tester lead to POSITIVE battery terminal.
c. Connect black clamp of tester lead to NEGATIVE battery terminal.
d. Attach inductive amp probe around red test cable. Arrow on probe must be facing the battery.
e. Remove surface charge from battery.
f. Set FUNCTION SELECTOR knob to BATTERY LOAD TEST.
g. Set LOAD CONTROL knob to the appropriate test load amperage. (See Figure 1.)
h. Wait approximately 15 seconds, then compare the voltage reading to the appropriate voltage specified in Figure 2.
i. If battery fails load test after fast charge, perform slow charge as described in Step 4.
4. Performs slow charge by charging battery for 24 hours at a rate not over 3 amperes. After slow charge, load test battery again. If battery fails load test after slow charge, replace battery.