Chinese electric vehicle manufacturer BYD has revealed new fast-charging tech that can add 400km (249 miles) of range from a five minute charge. With the announcement, BYD has also promised to make a major investment in charging infrastructure, building over 4,000 of the new fast chargers across China.

China is back with another engineering marvel. This time, in the form of BYD’s new battery system which is reportedly capable of charging an electric car in just five minutes – roughly the same amount of time as refueling a combustion vehicle.

Fast charging is viable, but experts say building the actual charging stations will be the tricky—and potentially very expensive—part.