How does an electric
car’s battery work ?

Increasingly present on the French and European roads, the electric cars are gradually replacing the thermic cars. And for good reason,driving them is enjoyable and silent, the maintenance is simple and fast, they are economical and favor eco-responsible driving. They don’t emit at all CO2 and release fewer fine particles than their thermic cousins.


Electric cars thus have numerous qualities. Still, as innovation is quite recent, it takes a little dose of courage to jump into the unknown. This is why we suggest you understand the functioning of the electric battery, the core element of these cars ! Once understood, it will be easier for you to adopt !

recharge vehicule electrique

Everything you need to know
about the electric battery :

Thermic or electric, an indispensable element is part of these cars and allows them to roll : their battery. Only, to make it work, you need to give it a boost, a source of energy !


While the thermic car uses gasoline or diesel as energy, this is not the case for its electric cousin. In fact, the latter functions due to two batteries :

  • The auxiliary battery ;
  • And the traction battery.
What is the role of the auxiliary battery and the traction battery in the electric car ?
The auxiliary battery :

All vehicles, thermic or electric, are equipped with an auxiliary battery. Its role : power the functioning of equipment integrated in the vehicles such as ventilation, headlights, radio, electric windows, etc.


If a failure happens with one of the accessories, it is often caused by this battery. Therefore, the auxiliary battery does not allow starting the car.

tableau bord voiture électrique
The traction battery :

The traction battery is the main element of the electric car. Its role is to store the energy needed by the car to roll. Once filled by the electric charging stations, the battery dispenses this energy to the motor during its trips.


The majority of cars are equipped with lithium-ion battery. In fact, this is the reference technology for the majority of manufacturers. It is durable, reliable, has a high performance level and, most of all, it benefits from a high safety level.
The other types of batteries for electric vehicle are :

  • The Nickel Metal Hydride battery ;
  • The Lithium battery ;
  • And the Cadmium Nickel battery.
How does the traction battery work ?

Imagine a set of small cells assembled together inside the battery. They form modules. Due to a chemical reaction between the electrons and the lithium atoms, each module converts the energy released into a current, and thus into electric energy. It is this energy which will then power the car’s electric motor.


The manufacturing of the traction battery is quite complex. This explains why it is the most expensive component of an electric car.


Now you know everything about electric batteries and their functioning. If you would like to know more about the durability of electric batteries, don’t hesitate to consult this article. Other chronicles are awaiting for you to help you become an expert in electric mobility, the energy transition and sustainable development !