In addition to an accessory battery (which is also found in internal combustion vehicles), electric vehicles have the particularity of also being all equipped with a traction battery. What is its role and how does it work? What is the future for these batteries? Our answers to the questions you have.
How does the traction battery in electric vehicles work
The traction battery is a fundamental element in your electric car. It is in fact the heart of your vehicle since it is used as an energy storage center to power the electric motor.
Currently, the traction batteries that allow the best autonomy are Lithium-ion batteries. They are therefore found in almost all electric cars.
The traction battery is controlled and protected by software called “Batteries Management System” or “BMS”. Her role? Preserve the health of the pack, and protect it from the risks of thermal runaway.
In fact, the traction battery is composed of several modules, each made up of a set of “small batteries”, called cells, which are connected together. It is imperative that these cells be charged and unloaded homogeneously.
If this is not the case, charge differences can cause premature deterioration of the batteries and even cause a risk of ignition.
Over the course of charge and discharge cycles, the battery degrades. Some manufacturers suggest resetting the BMS and thus reprogramming it, to give your battery a boost and improve its functioning. Batteries are generally guaranteed for 5 years, even if the intended lifespan is actually 10 years.
Traction battery and kWh: a question of autonomy
The battery charge capacity is measured in kWh (kilowatt hours). The more kWh your traction battery has, the more autonomy it has. This data should also be put into perspective with the power of the motor, expressed in kilowatts (kW).
For example, the Porsche Taycan Turbo S's traction battery has a capacity of 93.4 kWh, allowing it to travel 407 km to 462 km, on a single charge, according to the WLTP standard. That of the Renault Zoé is 53kWh, i.e. the equivalent of 171 km to 390 km with the same charging conditions.
Of course, the longer your traction battery will have, the more this will have an impact on the cost of your vehicle.
What is the future for traction batteries?
When your traction battery reaches the end of its life, it can then be recycled by specialized companies or reused to make stationary energy storage: a key element of smart grid. But also contribute to the electrification of vehicles, or even to the distribution of green energy in short circuits.
With the proliferation of electric vehicles, manufacturers are focusing on finding solutions to improve the lifespan of traction batteries. Thus, today's Lithium-ion batteries could be replaced within a few years by solid electrolyte batteries. The promises of this other type of all-solid battery are real, but not yet to the point on the part of the manufacturers.
Sources: The beautiful battery, EV expert, EDF, Clean car.
