Brake Energy Regeneration.

Until now, braking meant losing energy. Brake Energy Regeneration, a BMW EfficientDynamics technology, puts an end to this by winning energy back during braking to charge the battery.

As soon as the driver takes their foot off the accelerator the generator is engaged and converts excess kinetic energy into electrical energy. Once the battery is fully charged, the generator is disengaged from the engine. This unburdens the engine and reduces emissions. Fuel consumption savings means that there is more power available for acceleration.