Toyota Adopts Wireless Charging, For Phones
Wireless charging, of course, is also an exciting application that can be used to plug in electric cars, and that’s happening soon, too. Evatran’s Plugless Power will be offering aftermarket wireless kits to charge the Nissan Leaf and Chevy Volt. A number of other companies are in a headlong competition to sign up automakers with wireless options.
The Wireless Infiniti
The Infiniti LE version of the LEAF, due in late 2013, will also incorporate wireless charging, in conjunction with an automatic parking system.
The cellphone apps give a hint how the EV charging will work. To charge a cellphone, the Avalon owner simply puts the device on the no-slip sliding lid of the “eBin,” designed to both hide and connect electronics and located between the seats. A transmitter built into the lid connects to a receiver in the Qi-enabled phone and it starts charging. The charging feature can be turned off with a switch inside the eBin.
Moe Durand, a spokesman for Toyota, describes the Avalon as the company’s “flagship" and “very much a technology showcase.” Part of that, besides fancy displays and capacitive switching, is the Entune audio system, which accesses Pandora and other services through owners’ cellphones.
According to Nick Sitarski, an engineer at the Toyota Technical Center, the idea of incorporating wireless charging for those phones was hatched very recently, in January or February of 2012.
The Qi protocol for mobile devices is based on the principle of inductive charging, long used for such devices as electric toothbrushes and also the system used by Evatran and other companies wanting to retire the conventional EV charging station.
Qi was developed by the New Jersey-based Wireless Power Consortium to avoid the proprietary problem—cars with, for instance a Nokia charging system that could only handle Nokia phones. According to Menno Treffers, chairman of the WPC, 20 companies (with the notable absence of Apple) were active participants in developing Qi.
Some phones that are equipped with Qi out of the box are the Verizon HTC Droid DNA, LG Nexus 4, Nokia Lumia 929 and Android Windows HTC 8X. The iPhone and some others will work with Qi if equipped with an aftermarket sleeve.
A Tipping Point?
“This is a tipping point in the adoption of wireless charging,” said Treffers, who adds that the Avalon is the first in-car Qi application he’s seen. “It really shows there’s now an installed base of Qi phones, and that equipping cars to handle it is a benefit,” he said. “I think we will eventually see Qi in every car, though it may take a while.”
The Avalon lid isn’t sized to charge multiple devices at once, and that’s not really the goal with this type of inductive charging, where precise alignment really matters. A related form, magnetic resonant coupling, is more forgiving about distance, though Treffers warns that signals sent longer distances could create electronic interference, which could conceivably interfere with radio reception or other systems, such as tire pressure sensors.
There’s no Qi system for magnetic resonance, but that form, from WiTricity and others, also has applications for charging both in-car mobile devices and electric cars. WiTricity is partly owned by Toyota and has exploratory partnerships with other automakers.
The Proximity Issue
The cool thing about magnetic resonance is that a car wouldn’t have to be parked directly over its charging pad, and that a charging phone would be connected even if it was a few inches from the transmitter. You could simply throw your phone into or near a pad and it would charge (with some loss of efficiency at a distance).
Treffers says that inductive and magnetic resonance aren’t that different, and that the latter doesn't hugely extend the range of effective charging. “It’s a matter of a couple of inches,” he said. Maybe, but the reason Nissan is looking at an automatic parking option for the Infiniti LE is because of that proximity problem.
It’s simply difficult, with an inductive system, for the average motorist to line up his or her car with the transmitter on the garage floor. The old tennis ball on a string trick is good for lining it up vertically, but you need to line it up horizontally, too.
Automated parking is one approach, another might be an in-car screen and software that confirmed your position. I can’t say whether magnetic resonance or inductive charging will win the marketplace at this point, because both have distinct advantages. In any case, the Avalon eBin is the first step in what could be a long march with cars and wireless technology.
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