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

The battery rating that is tested at 32°F (0°C) is known as cranking amperes (CA). This rating measures the maximum amount of current a battery can deliver at a temperature of 32°F for a specified duration of time, typically 30 seconds, while maintaining a voltage drop above a certain threshold (typically 7.2 volts for a 12-volt battery).

This specification is particularly important for vehicles in mild climates where temperature conditions may not drop drastically. The CA rating helps ensure that the battery can crank the engine effectively under standard temperature conditions, enhancing starting reliability.

Cold-cranking amperes (CCA), on the other hand, measures battery performance at a lower temperature, specifically 0°F (-18°C), making it crucial for understanding how a battery will perform in cold weather. Reserve capacity measures how long a battery can run on its stored energy without being recharged, which is not dependent on ambient temperature. Lastly, the battery voltage test indicates the overall health of a battery but doesn't specifically measure current capabilities under cranking conditions.