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Toyota and WiTricity form wireless charging alliance

Toyota Motor Corporation (TMC) has entered into a technology collaboration agreement with WiTricity Corporation, an MIT spin-off commercializing an approach to “mid-range” wireless charging (distances from a centimeter to several meters), concerning the practical application of automotive wireless charging systems for automotive traction batteries and the promotion of their widespread use. TMC plans to participate in a WiTricity capital increase.

WiTricity’s technology is based on sharply resonant strong coupling, and is able to transfer power efficiently even when the distances between the power source and capture device are several times the size of the devices themselves. TMC believes that resonance wireless charging is suitable for automobiles and aims for its early practical use.

WiTricity’s technology is a non-radiative mode of energy transfer, relying instead on the magnetic near field. WiTricity proprietary source and device units are specially designed magnetic resonators that efficiently transfer power over large distances via the magnetic near-field. The magnetic field can wrap around a conductive obstacle between the power source and the capture device.

The power transfer efficiency of a WiTricity solution depends on the relative sizes of the power source and capture devices, and on the distance between the devices. Maximum efficiency is achieved when the devices are relatively close to one another, and can exceed 95%.

WiTricity is also partnering with Delphi (earlier post).

The collaboration is aimed to accelerate development and eventual implementation of wireless charging for automobiles. The charging of a plug-in hybrid or electric vehicle could be as simple and convenient as parking near an embedded charger at a home or in a parking facility.

In the Toyota Global Vision announced in March, TMC expressed its commitment to leading the way to the future of mobility by integrating automobiles, homes and information technology. Wireless charging is one of the many technologies TMC seeks to develop for the future.



Wireless charge spots may be common place by 2015. It will be followed by wireless charging equipment embedded into many streets-roads segments and parts of highways by the end of the current decade.

With access to more quick re-charge capabilities, many electrified vehicles may not need very large on-board batteries. That could reduce cost below ICE units.

City e-buses and e-taxis could eventually drive 24/7 without having to stop for long re-charge periods.


Delphi is smart to get into this. They went bankrupt a few years ago depending on GM and others, now they need to get in on the ground floor of an increasingly popular idea.


What ever system would be adopted it is crucial to have national/international wireless charging standard like we have Wi-Fi communication standards. Otherwise the idea of wireless charging will die. I heard Europe is working on that.


Wireless charge spots may be common place by 2015

Don't get carried away by you enthusiasm. We will be lucky if we have a reasonable number of wireful charging points in every city in 2015. That is already a huge undertaking, never mind wireless charging. That is post 2020 stuff.


Anne....to plug our electrified vehicles into a wall outlet or charger is too complicated, to inconvenient and too risky for the majority. The majority of future electrified vehicle owners will gladly pay the extra for wireless on-board charge equipment and facilities. Vehicles so equipped will benefit from wireless charge spots in many other places. Shopping centers, street side parking, banks, restaurants, cinemas, work places, private parking places, public parking places, etc will board the train quickly if there is a $$$ to be made. The quest for quick profits will be the main driver.


It depends on how you count the installations. If they are just commercial, I would say a standard would have to prevail. If they are home installations, the case may be different. People will pay $2000-$3000 for what amounts to an extension cord, would they pay more for an induction charger? I am guessing that they would.


Plugging something in is too complicated. Cell phones and iPods need to be plugged in, so they will never go anywhere! Oh, wait....


In all seriousness, WiTricity's system runs up against the health concerns about EMFs. It may be acceptable to have such fields around a vehicle when it's parked, but when it's occupied is another matter. This makes it unlikely that inductive charging will be integrated into roadways.

Conductive charging has much smaller concerns about these issues, and it's more efficient and cheaper to boot.


We will see how millions of people take to plugging their cars in every time they park. At first, the early adopters will be excited about less smog and no gas stations, but after a while the fun wears off.

It is my guess that the after market for induction chargers will be there for home use. Then many will want it on the new EVs they buy. It is hard to beat parking in the garage, the light comes on and you charge while you get the groceries out of the trunk.


This will enable charging beyond parking spots. Charging can take place at the stop light or even on the highway.

This technology will reduce or eliminate range anxiety and enable smaller battery pack hence affordable EVs.

Yuval Brandstetter

The method of charging is the easy stuff. the hard stuff is coordinating with the utility so that the neighborhood or parking structure transformer doesn't crash when more than a couple of EV's come it and connect, more so if its monster batteries. Thats' where Better Place has the real edge: Thier model is already at work.


Battery swaps seem like a good idea. You can charge many of them off peak and the swap takes 20 minutes and you are off and running.

I do not think this will be a popular method in the U.S. That is just my guess, but it requires way too much infrastructure to work. Americans are too independent to become dependent.


The problem with that model of battery swaps is the investment cost; needing more than 1 expensive battery per car (since the number required is set by peak demand, not average) drives the system cost up.

I suspect that the optimum may be to have different types of battery for different purposes. The every-day battery is built for long life and high energy efficiency. The range-extending battery is built for high energy density and low capital cost. It might not even be a "battery"; it might be something like a zinc-air fuel cell. But as long as it fits the form factor and electrical, thermal, etc. specs, it can be swapped in and run the car.

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