Achieving electric vehicle charging speeds comparable to refueling petrol or diesel vehicles has been the elusive next frontier, often cited as the “holy grail” of the EV technological evolution. Shenzhen-based BYD Co. promises to change that, having just unveiled a new battery-charging system for electric cars that the Chinese automaker says will allow some of its cars to charge almost as fast as it takes a regular car to refuel at a fuel pump. BYD’s new battery and charging system, which it calls the Super e-Platform, could provide 470 km of range in 5 minutes in tests on its new...