3 ms·What is "regen"?by happytoexplain 5y agoWhat is "regen"?garrettr_ 5y agoRegenerative brakingsp332 5y agoWhen you lift your foot off the accelerator, the car starts to run the motors "in reverse", charging the battery with some of your momentum. So the car slows gradually even if the brake pedal is unresponsive.