Saving while you brake.
Recuperation comes from the Latin word for recovery or reclamation. The principle can be explained as follows: when a conventional vehicle is braked, the brake converts the kinetic energy into thermal energy, which cannot be used for any other purpose. With a recuperation system, the kinetic energy is converted into useful electrical energy. While the vehicle is coasting or braking, the alternator voltage is raised above the level of the basic electrical system. During these phases the alternator can convert the vehicle’s kinetic energy into electrical energy, which is stored temporarily in the vehicle battery. When the vehicle subsequently accelerates or is driven at constant speeds, this energy is used to relieve the load on the alternator, allowing a fuel saving of up to 3%, depending on the driving cycle.