One-pedal driving in electric cars

IN 1894, WHENSUV Louis Antoine Krieger started making electrically powered horseless carriages (pictured above), he introduced a feature that had appeared earlier on some electric trains. The motors that drove the front wheels of Krieger’s landaulet could operate in reverse, to work as generators when the driver slowed down. That let them recover kinetic energy from the vehicle’s forward motion, turn it into electricity and use this to top up the battery. But there was another benefit. The harvesting of this otherwise-lost energy also produced a handy braking effect, helping slow the vehicle without the driver having to apply the somewhat dodgy mechanical brakes.Regenerative braking, as the technology Krieger used is now called, pretty much disappeared from road transport when electric power gave way to the internal-combustion engine. But, with sales of petrol- and diesel-powered vehicles peaking, and scores of new electric and hybrid cars appearing on the market, it is staging a comeback. Its principal advantage is that it increases the distance a vehicle is able to travel between charges. For example, according to its makers Audi, regeneration contributes 30% of the 400km maximum range of the firm’s e-tron . But regen braking, as it is known for short, also promises to do for the brake pedal what automatic gear boxes did for the clutch, and thus to make driving a one-pedal experience.