Automotive Electronics Practice Test

What battery rating is tested at 32°F (0°C)?

1. Cold-cranking amperes (CCA)

2. Cranking amperes (CA)

3. Reserve capacity

4. Battery voltage test

The correct answer is: Cranking amperes (CA)

The correct battery rating tested at 32°F (0°C) is cranking amperes, commonly abbreviated as CA. Cranking amperes measure the maximum current a battery can deliver at a temperature of 32°F for a duration of 30 seconds while maintaining a specific voltage, typically around 7.2 volts for a 12-volt battery. This rating is important because it reflects how well a battery can start an engine in moderate cold conditions, which is when temperatures begin to have a noticeable effect on battery performance. Cranking amperes are particularly relevant for ensuring that a battery can provide sufficient power to start the engine, especially in environments where temperatures may drop to levels where engine oil thickens and increases the resistance against engine turning. This is a vital consideration in automotive applications, as a vehicle’s starting system heavily relies on the battery's ability to provide enough current under these conditions. In contrast, other ratings—such as cold-cranking amperes, for example—focus on performance at much lower temperatures (specifically 0°F/-18°C), making cranking amperes more applicable to temperatures around freezing. Reserve capacity, which refers to the time a battery can provide a specified current before it drops to a defined level, and battery voltage