The Mercury Cougar cars use batteries mainly for providing electric current for starting the engine, and for operating the ignition and fuel injection systems besides running parts when the engine is switched off. The batteries also support critical services such as the clock and the component retainers during the time when the car is off. In the past, the Cougar has used mostly Conventional Flooded Lead-Acid batteries (FLA), FLA Maintenance-Free and the latest, the Absorbed Glass Mat (AGM) batteries. FLA batteries must be serviced, although FLA Maintenance-Free batteries need less servicing, but if they get damaged they will leak. AGM batteries, in contrast, has some great features such as it free from any maintenance, resistant to shock, and has higher starting power making it appropriate for rigorous usage. Car Batteries have some dimensions related to its size and other characteristics such as Cold Cranking Amps (CCA) and Reserve Capacity are important for a car Car Batteries to perform well in certain conditions.