The customer parks the car over a garage-floor charging plate, then comes back in the morning to a full battery Illustration: WiTricity
In the coming months, an unnamed manufacturer will bring an electric car to market that offers wireless charging from WiTricity, Alex Gruzen, the companys chief executive, tells IEEE Spectrum.
Unnamed, yes, but not utterly un-guessable. Among the companies that have demonstrated wireless charging are BMW and Hyundai. And, though there are other wireless charging companies out thereQualcomm, for exampleHyundai has explicitly named WiTricity as the supplier of the system it showed on its new Kona EV last week at the Geneva Motor Show. Other companies known to be working with WiTricity include Honda, Nissan, and Toyota.Photo: WiTricity A Hyundai Kona recharges with WiTricitys wireless system at the 2018 Geneva Auto Show.
Magnetic resonance was developed at MIT in the early 2000s.
It works by establishing a kind of
duet between an oscillating magnetic field in a pizza-box size
charger on the floor and a receiver
mounted under the car.
The charger and receiver are tuned to resonate, which is why little energy goes astray, making transmission as efficient as youd get from a cable.
"Theres often a misconception that somehow plugging in is 100 percent efficient," Gruzen says. "But a plug-in is from just 88 to 94 percent efficient; WiTricity's wireless system runs at 90 to 93 percent.
The resonance also gives you a certain leeway in aligning the car and the charging plate. The vertical clearance can be as little as 10 centimeters (4 inches), for a sports car, and as much as 25 cm, for an SUV. The left-to-right positioning need be only within 10 cm of dead center. The fore-and-aft errorwhich is easier for a driver to controlis 7.5 cm.
Drivers shouldnt take long to get the hang of parking close enough to the charger on the first try. That ease of use is the entire point.
About 70 percent of plug-in customers never bother to plug in, Gruzen says. They dont want to deal with cables. And broad, mainstream consumer behavior does not change, as it might with the 1 percent who are early adopters. I pl...