The six-cell, 12-volt lead-acid battery is located on the driver's side of the engine compartment. The battery capacity is determined by the amount of current needed to start the car, and by the amount of current consumed by the electrical system. Volkswagen batteries are rated by ampere/hours (Ah) and cold cranking amps (CCA) rating. The Ah rating is determined by the average amount of current the battery can deliver over time without dropping below a specified voltage. The CCA is determined by the battery's ability to deliver starting current at 0°F (-18°C).