section_path: Components and design/Propulsion and fuels/Batteries
section_name: Batteries
paragraph_text: Batteries
  
  In almost all hybrid (even mild hybrid) and pure electric cars regenerative braking recovers and returns to a battery some energy which would otherwise be wasted by friction brakes getting hot. Although all cars must have friction brakes (front disc brakes and either disc or drum rear brakes) for emergency stops, regenerative braking improves efficiency, particularly in city driving.