Last week Rolls-Royce revealed plans to build a 300-mile-per-hour, 500-horsepower, all-electric aircraft capable of flying from London to Paris on a single charge. The Accel relies on the most energy-dense battery pack every assembled for an aircraft—6,000 cells packaged together for lightness and thermal protection, combined with an advanced cooling system built to withstand extreme temperatures and high-current demands in flight. The nose-mounted propeller is powered by three high-density electric motors. The propeller spins at a much lower rpm than an aircraft with conventional propulsion, yielding a smoother and quieter ride. The all-electric power train runs at 750 volts while delivering 90% energy efficiency and zero emissions. Onboard sensors monitor 20,000 different points on the powertrain, measuring diverse metrics including battery temperature and battery voltage. When the Accel takes to the air in 2020, Rolls-Royce plans to set the speed record for all-electric flight (the current record is 210 […]