A battery’s capacity to start an engine in cold weather is measured using Cold Cranking Amps (CCA). A dedicated tester applies a load to a fully charged battery at 0F (-17.8C) and measures the sustained current delivered for 30 seconds without the voltage dropping below a specified threshold. For instance, a battery rated at 600 CCA can deliver 600 amps for 30 seconds at 0F. These ratings are essential for determining a battery’s suitability for specific vehicle makes and models, particularly in colder climates.
This measurement is crucial for ensuring reliable vehicle starting, especially in regions experiencing sub-zero temperatures. A higher rating generally indicates a greater starting power reserve. Historically, this metric became increasingly important with the rise of higher compression engines requiring more power to crank, and the expansion of automotive use into colder regions. Ensuring a battery with adequate cold cranking capacity prevents starting failures and the associated inconvenience and potential safety hazards.