Step 5 · Perform Load Test
Connect a carbon pile load tester to the battery terminals. Follow the tester's instructions, which typically involve applying a load equal to half the battery's cold-cranking amperage (CCA) rating for 15 seconds. While the load is applied, monitor the voltage reading on the load tester or a connected multimeter. The voltage should not drop below 9.6 volts during the test. If it drops lower, the battery is likely failing under load.