Capacity Testing

1. To carry out this test use a high rate discharge tester, Starter, Alternator, Battery, Regulator Tester (SABRE) in conjunction with digital multimeter.
2. Place the SABRE in the OFF position.
3. Place the digital multimeter selector switch in the AC volt position.
4. Connector SABRE and digital multimeter positive test leads to the positive battery terminal and both negative test leads to the ground battery terminal. The digital multimeter clips must contact the battery terminal and not the tester clips. Unless this is done, the actual battery terminal voltage will not be indicated.
5. Turn the load control knob in a clockwise direction until the ammeter reads approximately half the cold cranking amps of the battery.
6. With the ammeter reading the required load for 15 seconds, note the multimeter reading. Avoid leaving the high discharge load on the battery for periods longer than 15 seconds.
7. If the digital multimeter reading is more than 9.6 volts at 21 °C (70 °F), the battery has a good output capacity and will readily accept a charge, if required.
8. If the voltage reading obtained during the capacity test is below 9.6 volts at 21 °C (70 °F), and the battery is fully charged, the battery is damaged and a new one must be installed. If unsure about the state of charge, of the battery charge the battery.
9. After the battery has been charged, repeat the capacity test. If the capacity test battery voltage is still less than 9.6 volts at 21 °C (70 °F), install a new battery. If the voltage is 9.6 or more at 21 °C (70 °F), the battery is OK.
10. If the battery is found to be discharged only, check for a loose drive belt, loose electrical connection, charging system performance, and carry out battery drain testing. Drain Test