Why does the brake pedal in my hybrid Mercedes-Benz feel different the first time I step on the brakes after I start the vehicle and sometimes during normal driving?
Hybrid vehicles utilize regenerative and conventional hydraulic braking to reduce the speed of the vehicle. For regenerative braking, the kinetic energy of the decelerating vehicle is absorbed by the electric motor to generate a brake torque. The generated electrical energy is then fed to the high voltage battery for storage. Conventional hydraulic brakes utilize hydraulic fluid to apply pressure to the brake pads which squeeze against a rotating brake rotor. Friction is created between the pads and rotor which generate a brake torque to stop the vehicle. Depending on the driving conditions, the total braking torque requested by the driver can be divided into a regenerative component and a hydraulic component. If the required total braking torque can be achieved using regenerative means alone, then none of the braking is done hydraulically. In this case deceleration is achieved solely by using the electric motors to generate electricity. Due to the operating principals involved, the pe
