A German technology and engineering company has secured a patent for a wireless road-charging system designed to charge car batteries while the car is being driven.

The system by IAV Automotive Engineering uses electrical conductors fitted in the road to create magnetic fields. The conductors are equipped with sensors that activate them only when a vehicle is present.

The conductors also use controlled frequencies of alternating currents to ensure a high-efficiency electricity transfer to and from circuits in the road and the vehicle, says IAV.

The fully cordless system can also charge a vehicle even when it is parked.

The technology is not brand new and uses ideas from car manufacturer Nissan, which has created a wireless garage charger.

The US Department of Defence has also funded similar research at the University of California at Berkeley, where automated EV busses move along set tracks.

The system is expected to be commercially available within three years.