Regenerative braking is a process in which the car's kinetic energy during deceleration is used to generate electricity. To make this process most efficient, Mazda developed the i-ELOOP regenerative braking system that contributes to reducing electricity generation by the alternator, therefore minimizing fuel consumption. i-ELOOP captures the energy lost during deceleration, and saves it as electrical power in a revolutionary high-capacity Electri Double Layer Capacitor (ELDC). The Moment you step off the accelerator, the vehicle's forward momentum drives the alternator and starts charging the ELDC which quickly reaches full charge. Then when you step off the accelerator again, the stored electricity is used to power the car's electrical equipment. It's virtually free energy! The EDLC can stand an almost unlimited number of charge-discharge cycles, and combined with i-stop improves fuel economy.