The electric car offers a lot of innovative features. Among them: regenerative braking. Present on many vehicles, this technology makes it possible to extend battery life while limiting brake wear. How does it work? What vehicles are affected? Focus on this energy recovery system.
Regenerative braking: how does it work?
When you drive an electric car, the motor transforms the electric current into so-called “kinetic” energy. This energy makes it possible to move the wheels and accumulates over the kilometers. When braking, it is dissipated in the form of heat. What if instead of wasting it, it was possible to recover it?
That is the whole point of regenerative braking. This process consists in recovering the energy released when the car brakes in order to convert it into electrical energy. The aim: to reinject it into the lithium battery of your vehicle.
When you drive, this anti-waste process takes place in three steps:
1. When you release the accelerator pedal, the engine starts reverse and opposes the rotation of the wheels in order to slow the vehicle down;
2. The kinetic electricity of the wheels is transformed into electrical energy;
3. The motor recovers this energy to store it in the battery.
Is regenerative braking still useful?
The regenerative braking has several advantages:
· For an electric car: it increases its autonomy and allows you to gain several additional kilometers depending on the situation.
· For a non-rechargeable hybrid car: external charging is not necessary. Regenerative braking recharges the battery for ultimate fuel savings.
In addition, by decelerating, the engine slows the vehicle down without using traditional brakes. The latter will then be damaged less quickly, for reduced maintenance costs and better longevity. Using the brake pedal less also leads to real driving comfort and smoother stops. The only condition: adopt an economical, less abrupt and jerky way of driving.
Because of how it works, regenerative braking is particularly useful when there are frequent decelerations. This is especially the case in urban areas or downhill such as on a mountain road.
Conversely, this energy recovery system is not very effective at low speeds (a traffic jam for example), because the braking force is not sufficient to generate electricity. This is also the case on motorways or expressways, where few stops are necessary.
What vehicles are affected?
A large majority of electric and hybrid vehicles incorporate a regenerative braking system. Its mode varies from manufacturer to manufacturer:
· One-pedal driving” (one pedal in English)
This system goes as far as the vehicle comes to a complete stop and does not require the use of a mechanical brake. Here, simply release the accelerator pedal to brake. This technology is present on some models dedicated to urban use, such as the Nissan Leaf or the Honda e.
· Flexible regeneration
Manufacturers like Hyundai and Kia are integrating this solution. It allows drivers to choose the level of braking intensity that is right for them, usually using paddles at the wheel.
· B mode
This system is present at Peugeot, Citroën, Opel and DS. The vehicle has two modes: “D” (Drive) to drive with little regeneration; or “B” (Brake) to fully benefit from regeneration. The latter is set in a fixed manner.
Tesla: regenerative braking improved with Autopilot
The regenerative braking is an important feature of the electric car. To make it even more effective, Tesla recently rolled out a new update. It concerns Autopilot, its automated driving system.
Until now, Autopilot used mechanical braking and regenerative braking in a more or less balanced way depending on the situation. With patch 2022.04., it will make greater use of regenerative braking at low speeds. Drivers will thus be able to enjoy a better driving experience, especially in the city.
For older models, two braking levels were offered: Standard or Low. For newer vehicles, it is no longer possible to choose regenerative braking parameters: they are set automatically.
Sources: Futura, honda, Phonandroid, Numerama, Vehicle Answers.
