Battery Load Test
WARNING: This page is about a different car, the 1999 GMC Sierra and 1999 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Before performing the load test, visually inspect the battery for obvious damage, such as a cracked or broken case. If the battery is damaged, replace the battery.
- Load testing requires the battery to be in a fully charged state in order to obtain an accurate test. When load testing the battery out of the vehicle use GM P/N 12303040 to ensure good connections.
- With the load in the tester turned OFF, connect a corbon pile load tester and the J 39200, or equivalent digital multimeter, across the battery terminals. With all loads off and the green dot showing in the hydrometer, the voltage should be 12 V or higher. Unless the battery has just been discharged (such as by a load test or cranking the engine), replace the battery if the voltage is below 12 V.
- With the J 39200 still attached, connect a battery load tester across the battery terminals.
- If the battery has been charged recently, apply a 300 ampere load for 15 seconds in order to remove the surface charge from the battery. Remove the load. Wait 15 seconds in order to let the battery recover.
- The battery temperature must be estimated by touch and also by the temperature the battery has been exposed to during the preceding few hours.
- Apply the specified load located on the battery label or listed in the battery specifications table.
- Read the voltage after 15 seconds. Then remove the load.
- If the voltage drops below the minimum value listed, replace the battery.
- If the voltage does not drop below the minimum value, the battery is good and should be returned to service.
NOTE:
Do not remove the surface charge from the batteries that have been in storage.