Ratings
What Is CCA (Cold Cranking Amps)? SAE, EN and DIN Ratings Explained
What cold cranking amps measure, how SAE, EN and DIN test methods differ, why CCA cannot be converted to Ah, and how much CCA your vehicle really needs.
Cold Cranking Amps (CCA) describe how much current a starting battery can deliver in freezing conditions — the moment an engine is hardest to turn over. It is a measure of power, not of stored energy.
The SAE definition
Under SAE J537, CCA is the current a new, fully charged 12 V battery can deliver at −18 °C (0 °F) for 30 seconds while keeping a voltage of at least 7.2 V.
SAE, EN, DIN, JIS: why the numbers differ
European (EN), older German (DIN) and Japanese (JIS) standards use different test durations and end-voltage criteria. The same battery can therefore show different numbers depending on the standard printed on the label. Only compare CCA values measured under the same standard. Battery Atlas always shows the standard next to every CCA value.
Related ratings
- CA / MCA (Cranking Amps / Marine Cranking Amps): measured at 0 °C (32 °F), so the figure is higher than CCA for the same battery.
- RC (Reserve Capacity): minutes a battery can supply 25 A at 27 °C before falling to 10.5 V — useful if the alternator fails.
- Ah (amp-hours): stored charge, normally at the 20-hour rate.
Can CCA be converted to Ah?
No. CCA depends on plate surface area and internal resistance; Ah depends on the amount of active material. Two batteries with the same Ah can have very different CCA. Any "CCA to Ah formula" found online is at best a rough correlation for one product family.
How much CCA do I need?
- Use the vehicle manufacturer's minimum specification — it is the only authoritative value.
- In cold climates choose a battery that meets or exceeds that value.
- More CCA than specified does not harm the vehicle, provided size, terminals and technology match.
If no OEM figure is available, our CCA calculator gives an orientative estimate based on engine displacement.