Your car’s battery cold cranking amps requirements are determined by engineers that help design the car’s engine and electrical system. The battery has to have enough power available to power the ignition system, turn the engine over and usually to power a fuel pump in order to start the vehicle. The car’s starter motor, which is what turns the engine over while starting, is the largest single drain on your car’s battery. Heat makes it harder for the starter to turn the engine over, requiring more cold cranking amps to do so. If you live in an especially hot weather area, you might want to look into a battery that delivers 100 cold cranking amps more than the minimum specified for your car to ensure adequate starting power even on the hottest days.
For more info, see Getting the Best Car Battery Prices