Load testing requires use of battery side terminal adapters (AC Delco part number ST-1201, GM part number 12303040 or equivalent) in order to ensure good connections. Do not load test a frozen battery. Replace it instead refer to Battery Replacement .

1. Use a voltmeter in order to check voltage across terminals. With all loads off, and a green dots showing in the hydrometer, voltage should be 12 volts or higher. If not, replace the battery refer to Battery Replacement .
2. With the voltmeter still attached, connect a battery load tester across the battery terminals.

Important: Do not apply amperage or remove the load if the battery has not been recently charged.

3. If the battery has been on charge, apply a 300 ampere load for 15 seconds in order to remove the surface charge from the battery.
4. Remove the load.
5. Wait 15 seconds in order to let the battery recover. Apply the specified load located on the battery labe or refer to Battery Usage .
6. Read the voltage after 15 seconds, then remove the load.

Important: You must estimate the battery temperature by feel and by temperature that the battery has been exposed to for the proceeding few hours.

7. If voltage does not drop below the minimum, the battery is good and you can return the battery to service. Refer to Battery Hydrometer Displays Dark or Yellow Dot .
8. If the voltage drops below the minimum, replace the battery. Refer to Battery Hydrometer Displays Dark or Yellow Dot .