Battery 101: CCA Explained

What is CCA

CCA stands for Cold Cranking Amps. It is a measure of a battery’s ability to deliver a short burst of high current which is used to start an engine. This rating is usually displayed on the top label of starting/cranking batteries.

How CCA Is Measured

CCA is a measure of how well a battery will start an engine while in a cold environment. To measure CCA, the battery is tested at -18°C (0°F) which is below any temperatures experienced in Australia and New Zealand. The CCA will tell you how many amps a battery can support over 30 seconds at this temperature, before dropping below a designated voltage.

Here’s how the test is performed:

• The battery is cooled to a temperature of -18°C (0°F).
• The battery is connected to a carbon pile tester and loaded at its CCA rating for 30 seconds.
• During this time, the voltage must not drop below 7.2 volts

The test result is either a Pass or Fail. If the battery can supply the rated CCA for 30 seconds without dropping below the voltage limit, it Passes the test. If not, it Fails.

How much CCA do I need?

Going for the highest CCA you can find isn’t necessarily the best for your vehicle. If the CCA requirement of your vehicle is met there is no need to look for a higher rating. To find the CCA rating for your vehicle, you can follow one of the 3 methods below:

Search your vehicle on R&J Batteries’ Battery Finder

Enter your vehicle’s make and model, or registration number, into the R&J Batteries Battery Finder to generate a list of suitable batteries. This list will include CCA and other specifications that are a suitable fitment for your vehicle. It will also note any possible upgrade options or installation tips and tricks.

It’s important not to go below the recommended CCA or Ampere Hours (Ah) ratings. If you do, the battery may fail prematurely or even struggle to start. Once you find the correct CCA required for your vehicle it’s advised to replace it with an equivalent model or to upgrade.

Check your car manual

Another way to know the right CCA is to check your vehicle’s manual. The manufacturer will have noted what CCA or Ah your vehicle requires and what rating the original (OEM) battery had.

Check your previous battery

Lastly, to check what CCA battery rating your vehicle needs, you can look at the previously installed battery.

• Check the top label of the battery currently in your vehicle
• Note the CCA rating
• Find a replacement with the same CCA rating or greater
• Ensure the dimensions are the same

Replacing your Vehicle’s Battery

It’s also very important to replace your vehicle’s battery with an equivalent or better battery type and CCA rating.

Modern cars have more electronics like screens, sensors, safety systems and Idle Stop Start technology (ISS). These demand greater battery performance and may mean your vehicle is required to meet minimum CCA or Ah ratings along with requiring specific battery types. 

Calcium is the bread and butter of the modern car battery (read more in this article), followed by Enhanced Flooded Batteries (EFB) then finishing at the top with Absorbent Glass Mat (AGM) batteries. If taking out an AGM battery you must replace it with an AGM battery, while a calcium battery could be upgraded to an EFB, or an EFB to an AGM.

It is important that you should avoid downgrading. If a vehicle was originally fitted with an EFB, downgrading to a Calcium will likely result in premature battery failure and will void the battery warranty.

Is Higher CCA Better?

How much CCA do you really need? Is bigger always better when it comes to starting a vehicle? The answer is no, if the CCA requirement for your vehicle is met, there is no need to look for a battery with higher CCA. Installing a higher CCA battery will not improve its ability to start the vehicle.

For many years CCA has been used as a benchmark for batteries based on the assumption that a higher CCA battery is better and will last longer. This assumption is incorrect, and in some cases the opposite can be true.

To increase the CCA rating of a battery you need to increase the plate surface area within each cell. This is achieved by adding more plates which may need to be made thinner to fit. Thinner plates are less dimensionally stable, meaning they are more likely to distort and potentially short circuit, and will often degrade at a faster rate.