Nissan unveils induction charger

The sight of electric cars umbilically attached to their charging stations hasn’t yet become common-place but already the technology is about to be superseded.

Nissan in Japan this week showed journalists a glimpse of the very near future in the form of a wireless charging station for its Leaf electric car. Present day electric vehicle charging technology requires the connection of a cable to the vehicle in order to recharge its battery via mains electricity.

But Nissan has developed a wireless charging pad that recharges the battery simply by parking the vehicle on top of a ground transmission unit. Much like the charging system on electric toothbrushes the Nissan wireless charger works by electromagnetic induction, as opposed to conduction which is when you connect a power cord to a socket.

Electricity is drawn from the recharging coil in a housing mounted on a garage floor or driveway and into contacts inside the vehicle. The idea is to make charging your EV something you never have to think about: you simply drive into the garage at night, taking care to park squarely over the charging pad, and then leave the car to charge itself.

By the time you come back in the morning the car is fully charged and you’re on your way.  The system is tolerant of variations in alignment of up to 100mm and is 90 per cent as efficient in terms of power transmission as a cable system, meaning it will charge the Leaf electric car in about eight hours.  

Experts say there’s no physical danger if a child or animal were to crawl into the 150mm gap between the car and the transmission unit as the unit transmits at a low three-to-six kilowatts. Researchers in Korea are reportedly already working on an electric bus powered by a continuous inductive connection with a cable buried in the road.

The scenario of induction highways that allow EVs to make intercity journeys without stopping to recharge may no longer be the stuff of science fiction.