What battery rating is generally used to determine the load to apply when load testing a battery?

The correct battery rating used to determine the load to apply when load testing a battery is Cold Cranking Amps (CCA). CCA is crucial because it indicates the battery's ability to start an engine in cold temperatures. This rating reflects how much amperage a battery can deliver at 0 degrees Fahrenheit for 30 seconds while maintaining a voltage of at least 7.2 volts.

When load testing a battery, applying a load that equals about half of the CCA rating for 15 seconds is a common practice. This test helps ensure that the battery can handle the necessary power demands during startup, which typically draws a significant amount of current.

Other ratings like Marine Cranking Amps (MCA), Cranking Amps (CA), and Reserve Capacity (RC) are useful in different contexts but do not provide the same direct measure of a battery's cold starting capability. MCA, for instance, measures the battery's performance at 32 degrees Fahrenheit, while CA is similar but generally conducted at warmer temperatures. RC indicates how long a battery can sustain a specific load but is not directly related to engine starting performance. Thus, CCA is the most relevant rating for load testing a battery, particularly in colder conditions.