Cranking amps — What does the term mean?

Cranking amps are different than cold cranking amps and it’s really not a meaningful term in you drive in cold weather

To properly rate a battery’s ability to start a vehicle, you have to test it at an industry defined temperature, for an industry defined time period, with an industry defined maximum drop in voltage. Here’s the definition of cranking amps (CA):

Cranking amps definition

Cranking amps (CA) refers to the number of amps a battery can output at 32°F (0°C) for 30-seconds while still maintaining at least 7.2 volts. The reason cranking amps is more important than peak amps is that people usually use a jumper pack to start their car in cold weather. Batteries produce power through a chemical reaction and that reaction slows when it’s cold. So you want a rating that’s based on a set temperature, which peak amps don’t have.

In addition to temperature, you also want to know how long a battery can output the specified number of amps. Think about it, what good is a battery that puts out more amps but for such a short enough period of time that it can’t start your engine.  Finally, when the battery voltage drops below a certain point, it can no longer operate the starter motor. That’s why CA covers total amp output at a set temperature, for a set period of time, all while maintaining a voltage above a set minimum.

Cold cranking amps (CCA) is like CA except that the rating is based on amperage output at 0°F (-17.8°C).

If you live in Southern Climates where it never gets below 32°F, then CA is a valid way to gauge a battery’s ability to start your car in cold weather. However, if you live in a colder climate, you should shop for a battery based on its cold cranking rating. See this post for more information on cold cranking amps

©, 2020 Rick Muscoplat