What are cold cranking amps?
Cold cranking amps (CCA) are an important indicator of a
battery’s ability to start your car in cold weather. In fact, it’s the single most important rating. Since a lead acid battery produces power using a chemical reaction, and that reaction slows down in cold weather, it’s important to buy a battery with a high enough cold cranking amp rating. Here’s what cold cranking amp and cranking amp ratings mean
Cold cranking amp rating
A car battery’s cold cranking amp rating is based on an industry standard test that tests how many amps a battery can deliver for 30-secs at 0°F while still maintaining a cell voltage of at least 1.2-volts, or a total battery voltage of 7.2 volts. The cold cranking amp rating is dependent on the size and number of lead plates, the type of construction used to form the plates. Typically, car batteries range from 350 CCA to as much as 800 CCA.
In general, the larger the battery and the higher the number of plates, the higher the CCA rating. As you can see in this chart from a Toyota service manual, the battery with 48 plates provides 350 CCA, while the battery with 84 plates provides 560 CCA.
Should you buy the battery with the most cold cranking amps?
Not really. Late model vehicles control charging rates from
the engine control computer and the computer assumes you’ve used the recommended battery. If you replace your battery with a different size or a battery with a different cold cranking amp rating, you may possibly damage the new battery by undercharging it or charging at too slow or fast a rate.
What are cranking amps?
Cranking amps (CA) is a rating similar to cold cranking amps where the battery is tested to measure how many amps it can provide for 30-seconds at 32°F while still providing at least 1.2 volts per cell (7.2 volts for a 12 volt battery).
©, 2017 Rick Muscoplat