Battery Load Test

TOOLS REQUIRED
ST-1201 GM P/N 12303040

Load testing the battery out of the vehicle requires using side terminal battery adapters on the battery to make good connections.

Before performing the battery load test inspect the battery:
^ Check for a cracked or broken case that permits loss of the electrolyte.
^ Evidence of small amounts of electrolyte leakage around the vent holes does not necessarily indicate the battery is defective. The leakage can be caused by tipping or overcharging the battery.
^ Check for faulty battery terminals.
^ Check the hydrometer. Refer to Battery Hydrometer Displays Dark or Yellow Dot. Battery Hydrometer Displays Dark or Yellow Dot

Do not load test a frozen battery. A frozen battery must be replaced. Refer to Battery Replacement. Service and Repair
1. Connect a voltmeter and a battery load tester to the battery terminals.




2. If the battery has just been charged or used in a vehicle:
2.1. Apply a 300 A load for 15 seconds to remove the surface charge from the battery.
2.2. Remove the load.
2.3. Wait 15 seconds in order to let the battery recover.

3. Apply the load specified on the battery label.
4. After 15 seconds, read the voltage then remove the load.

IMPORTANT: The battery temperature must be estimated by the feel and by the temperature the battery has been exposed to for the preceding few hours.

5. The battery is good and can be returned to service If the voltage does not drop below the minimum voltage. Refer to Battery Temperature vs Voltage Drop. Replace the battery If the voltage is less than the minimum.