A car battery is an electrical storage device it doesn't make electricity it simply stores the power until you are ready to use it.
When starting the car, the battery supplies power to the starter motor to turn the engine over.
At the same time, more power from the battery is supplied to the spark, or glow plugs to ignite the fuel mixture compressed in the engine cylinders to make it run by itself
The battery power used during starting is then replaced by the alternator, which supplies the bulk of electrical current to your car's electrical systems, keeping a healthy battery fully charged.
As well as having to start the car the battery has to power all the in-car technology items like air conditioning, digital music players, satellite navigation systems and other electronic gadgetry.
This all increases the demand on cars’ battery and charging system gradually degrading the battery. Consequently more frequent checks are recommended so that your car battery is maintained at its’ optimum working level.
The demand from a battery is at its highest staring a car on a cold winters morning. This is when an unhealthy battery can let you down
Regular battery checks can help identify and prevent premature ‘battery failure’, which can result in a vehicle breakdown at these most inconvenient times.