Regenerative Braking Explained: How Electric and Hybrid Cars Recover Energy

 Hybrid and electric cars have a clever trick: they turn braking into charging. Instead of wasting the energy of a moving car as heat, they send some of it back to the battery. It's called regenerative braking, and it changes how these cars feel to drive.

In a hybrid or an electric car, slowing down also charges the battery.

How it works

When you lift your foot off the accelerator, or press the brake pedal gently, the electric motor works in reverse, as a generator. That slows the car down and sends energy to the battery. The normal friction brakes (pads and discs) are still there, and they take over for harder stops and for the last bit of slowing down.

Why it matters

It helps the car use less energy, especially in city traffic with lots of stopping and starting. It also means the brake pads and discs are used less, so they often last longer than in a normal car.

One-pedal driving

Some electric cars slow down quite strongly as soon as you lift off the accelerator, so you can drive most of the time without touching the brake pedal. Many cars let you change how strong this is in the settings. It takes a day or two to get used to it. And in most cars, the brake lights come on when the car slows down this way, so the drivers behind you can see it.

When it's weaker

Regenerative braking doesn't always work the same. It can be weaker when the battery is almost full, because the energy has nowhere to go, when the battery is very cold, and at very low speeds. You may notice the car slows down less than usual, and the normal brakes do more of the work. So always leave a safe distance, and don't count on the same slowing down every time.

On a slippery road, a strong setting can feel abrupt. If your car lets you, choose a lower setting in the rain or on ice, and drive smoothly.

Looking after the brakes

Because the friction brakes are used less, they can rust or stick. Have them checked regularly, as your manual says, and don't skip brake fluid changes. If you notice a noise, a vibration or a longer stopping distance, get it looked at.

General information only. Electric and hybrid cars vary a lot, so follow your owner's manual and leave high-voltage work to a qualified technician.