A car cannot run without a battery. A battery is a rechargeable element which supplies electrical energy to the car. Its main purpose is to start the engine. While the engine is running, most of the power is provided by the alternator, which includes a voltage regulator. Its also called an SLI battery which means starting-lighting-ignition. They are lead-acid type and provide electrical energy to the car. In the modern generation, car batteries are designed in such a way that the maintenance is very easy and its cost less too. A car battery can be drained off completely when the headlights of the car are switched on unknowingly.

Batteries are typically made of six galvanic cells in a series circuit. Heat is the main cause of battery failure as it accelerates corrosion inside the battery. Batteries can be recycled so that the resources used to manufacture new batteries will be less. Earlier cars did not have batteries as their electrical systems were limited. A bell was used instead of an electric horn. Car batteries became widely in use in the 1990’s when cars had electrical starters. Batteries are usually grouped by physical size, type and placement. When a vehicle has a flat battery it can be jump started by another battery of another vehicle.

Car batteries are extremely important elements of the car without which the car cannot run. Few heavy vehicles use more than one battery because it requires more energy and power to run the vehicle.
There are different brands of batteries like Autocraft, Bosch, DieHard and Duralast among many others.
The battery is an important component of a vehicle because it supplies power to the motor, the lights and the ignition.

These are few indications to tell that the battery has drained:
The battery ammeter lights up
There will be starting problems, the car may not start immediately because the battery will not be able to supply enough power to the other components.
There might be a bad odor coming from the car which is also a sign for battery failure.