What do Ah, CCA and EN mean on a car battery?

When comparing car batteries, you will often see designations such as Ah, CCA and EN. These describe different battery characteristics.

Ah – Ampere-hours

Ah indicates the battery’s nominal capacity: how much electrical charge it can deliver under specified test conditions.

A 70 Ah battery, for example, has a higher nominal capacity than a 50 Ah battery.

However, this does not mean the battery can always deliver 70 amperes for one hour. Actual capacity is affected by factors including load, temperature and battery condition.

CCA – Cold Cranking Amps

CCA indicates the battery’s ability to deliver high current at low temperatures.

This is particularly important for starter batteries because the starter motor needs a lot of current to start the engine.

A battery with a higher CCA rating generally has a better ability to deliver high starting current, provided the values are measured according to the same standard.

EN – European standard

EN indicates that the battery’s starting current has been measured according to a European test standard.

For example, you may see the label:

70 Ah – 760 A (EN)

This means the battery has a nominal capacity of 70 Ah and a stated starting current of 760 amperes according to the EN standard.

What matters most when choosing a battery?
Both capacity and starting current are important, but the battery must also have the right technology, dimensions and electrical characteristics for the car.