Canadian Researchers Create Wireless Charger For Electric Cars

An anonymous reader writes "University of British Columbia researchers have developed a wireless charging system for electric cars. It involves a spinning magnet beneath the parked vehicle which turns another magnet in the underside of the car. Charging takes four hours and is about 90% as efficient as plugging in. From the article: '"One of the major challenges of electric vehicles is the need to connect cords and sockets in often cramped conditions and in bad weather," says David Woodson, managing director of UBC Building Operations. "Since we began testing the system, the feedback from drivers has been overwhelmingly positive." Four wireless charging stations have been installed at UBC's building operations parking lot. Tests show the system is more than 90 per cent efficient compared to a cable charge. A full charge takes four hours and enables the vehicle to run throughout an eight-hour shift.'"

Comments

efficiency: 90% of cable?

[AliasMarlowe]

OK, so it can double as a garage heater in winter. However, in the snowier parts of the country (i.e. NOT Vancouver and its suburbs), this will not be appreciated for outdoor use - lots of meltwater turning into smooth ice...

Re:efficiency: 90% of cable?

[Anonymous Coward]

Let's see if you're right. A Tesla Roadster has a 50kWh battery. Charging that in 4 hours requires 12500W of power. 10% of that is lost compared to the cable charger. That's 1.25kW of heat in addition to the heat from the inefficiencies of the rest of the charging system and the battery. That's in heater territory, but not enough to significantly heat an uninsulated garage. Problems with molten ice and snow can't be much different from parking a car with a warm engine.

Re:Why the second magnet?

[Latentius]

Nevermind...finally read the article thoroughly. They're just placating the idiots who think that other types of wireless power transmission is black magic or something, as if quickly rotating magnetic fields (not to mention large magnetic discs) is any safer than electrical fields alone. Apparently these people have never heard of electromagnetism and aren't aware that the two are intrinsically linked.

F-Zero

[Anonymous Coward]

I have visions of the recharge lane.

Re:F-Zero

[Latentius]

Joking aside, that's not a half-bad idea. Even if we're talking about the non-magnetic forms of wireless power transmission, it could be possible in the distant future to embed the technology in our highways and have it powered by roadside solar panels, etc.

Existing tech

[trout007]

This is used all of the time in pumps where you don't want a dynamic seal. You have permanent magnets spun by a motor and inside a sealed case the pump is coupled by a magnetic field.

http://www.proconpumps.com/brands/Magnetically-Coupled-Pump-(Sealless).html

Re:90% as efficent as a plug is good enough?

[AmiMoJo]

Tesla Motors is deploying solar power charging stations. When the fuel is free the 10% loss is worth it for the simplicity of having a car park where every space automatically re-charges your car, included in the cost of the ticket.

Brilliant Idea, but One Suggestion

[mtrachtenberg]

Brilliant. I'd make a teensy change. Replace the spinning magnet outside the car with a cable, and replace the spinning magnet and generator in the car's underbody with a plug. Run power through the cable to the plug, but only after there's been a handshake between the cable and the plug. Use the equipment that would spin the magnets to establish a physical connection between the cable and the plug.

I think the efficiency of this, compared to old techniques, will be closer to 100% of existing efficiency than to 90%.