Carbon Pile Load Test

Carbon Pile Load Tester:

CARBON PILE LOAD TEST

NOTE:

^ The battery must be fully charged for this test to be valid.
^ Do not remove surface charge from stored battery.

1. Connect a voltmeter and battery load tester across the terminals of the battery as follows:

In-Vehicle: If the battery is in the vehicle, connect the battery tester cable to the terminal bolts being careful not to touch surrounding bare metal on the vehicle.

Out-of-Vehicle: If the battery is out of the vehicle, connect the carbon pile load tester to the terminals, according to manufacturer's instructions.

2. Remove surface charge from the battery if it has just been on charge and the green dot is visible. This includes batteries in the vehicle having been charged by the charging system of the vehicle.

NOTE:

Do not perform this step on batteries that have been in storage.
To remove the surface charge:
^ Apply a 300 amp load across the battery terminals with a carbon pile load tester for 15 seconds.
^ Then turn the load off and wait for 15 seconds to allow the battery to recover.

3. Estimate the battery temperature as follows:
The battery temperature should be estimated by the surrounding temperature it was exposed to during the preceding few hours before testing. On the chart below, select the nearest estimated temperature to determine the minimum voltage specification that must be maintained during the load test.

Minimum Temperature Voltage
Above 70°F (21°C) 9.6V
50°F(10°C) 9.4V
20°F(-1°C) 9.1V
15°F(-l0°C) 8.8V
0°F(-18°C) 8.5V
Below 0°F 8.0V

4. Observe the load value specified for testing this battery from the label on the top of the battery. With a carbon pile tester, apply this load for 15 seconds. With the load still applied at the end of this period:
^ Observe the terminal voltage on the voltmeter. Then turn off the load.