A Japanese car maker has started field trials with a wireless charging system, which allows electric cars to recharge their batteries through magnetic resonators buried in the road surface of a parking space.

Toyota’s new technology does away with the need to plug the car into electricity mains using a cable.

The wireless charging device is contained in a mat, which measures about 50cm across.

When the electric car is parked, the mat is raised automatically and the AC power is delivered via the magnetic field that is created under the electric vehicle, the Daily Telegraph reported.

The first phase of testing will start in Toyota City in January.

Toyota says a typical Prius-sized model could be recharged in 90 minutes using the wireless induction system - the same amount of time needed for conventional cable charging.

One slight drawback is that drivers who do not position the car directly above the magnetic mat will find that charging takes slightly longer.