What are CCA?

Cold cranking amperes (CCA) is an international standard for measuring the performance of a battery. CCA measures the cranking capacity of a battery at a temperature of -18C (0F). To get technical the rating is defined as the number of amperes a lead-acid battery at -18C can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12 volt battery).