How do you recover energy from braking?
Regenerative Braking - it recaptures the energy that is lost to braking. The motion is converted to energy instead of heat.
Any electric motor can be used as a generator. To recover energy, you just attach the motor to the wheels and watch the current flow the other way. It will take energy to power the generator, and this slows down the car.
Here is a link to a site explaining electric motors and generators.