Question

A battery high rate discharge (load capacity) test is being performed on a 12 volt battery. Technician A says that a good battery should have a voltage reading of higher than 9.6 volts while under load at the end of the 15-second test. Technician B says that the battery should be discharged (loaded) to twice its CCA rating. Which technician is correct?

Answer 1

Technician A is correct in stating that a good battery should maintain a voltage higher than 9.6 volts under load after a 15-second test. Technician B is incorrect; discharging a battery to twice its CCA rating can cause damage.

Step-by-step explanation:

The subject in question involves a high rate discharge test of a 12-volt battery. Technician A's assertion that a good battery should maintain a voltage reading higher than 9.6 volts under load after a 15-second test is a commonly accepted standard. Therefore, Technician A is correct. Technician B suggests that the battery should be discharged to twice its CCA (Cold Cranking Amps) rating, which is incorrect and potentially harmful to the battery because doing so can cause excessive stress and damage to the battery cells. The CCA rating is a measure of the maximum amps a battery can deliver at 0°F for 30 seconds while maintaining at least 7.2 volts (or 1.2 volts per cell for a 6 cell battery). Normally, during a load test, a battery should be loaded with a current equivalent to half of its CCA rating.

Answer 2

The answer to the question is

Technician A is correct.

Step-by-step explanation:

To Load Test a battery, an electrical load equivalent to one half of the CCA rating is applied to the battery for 15 seconds. A good battery's voltage reading should be above 9.6 volts while carrying the electrical load.

The state of charge of the battery should be not less than 75% before the battery is load tested.

To determine the state of charge of a battery, an open circuit voltage test is performed.