Wireless charging?

Wireless charging?

Powermat, the company that makes wireless charging for cell phones and other small appliances, is currently working with Chevrolet to initially provide a powermat between the seats to charge mobile phones in the Volt. Longer term they plan also to charge the vehicle itself. Surely this is obvious technology that Tesla should be looking seriously at including, even if only as an option, in the model S. The technology for small products is mature and is out there.

Vawlkus | July 18, 2011

Tesla is not, since they are building the CARS, and NOT the chargers.

There are several companies looking into this technology, but there are still significant power loss issues that have to be dealt with.

dborn | July 20, 2011

Here is a comment from a review of a Rolls Royce concept electric vehicle.

"Increase the range to 400km and it’s a fair bet that it would walk out of the showroom doors. Battery technology is not quite able to allow such a feat yet, but it’s certainly on its way. There’s even induction charging available to ensure convenience is covered – if you’re interested, the efficiency difference between plugging the 102EX into the wall and parking it over an induction loop to charge is around three percent. Induction is extremely effective."

dborn | July 20, 2011

The link above is not correct - this one is.

Volker.Berlin | July 20, 2011

Interesting quote. There are some more comments on induction charging in this thread:

Yuanben | July 28, 2011

Charging on red light stop could be a brilient idea, but how is the battery would be affect by multiple small charge?

Vawlkus | July 29, 2011

LI-Ion batteries don't mind getting a little charge here and there; that is how the regenerative braking system works to recharge the battery afterall.

jomo25 | August 3, 2011
msiano17 | August 3, 2011

Here is some good news,

throughout the site there has been the chatter about best places for charging stations, gas stations are set up already for it and so forth ...

well a colleague at work is invested into a company that is setting up charging stations supposedly at Cracker Barrels and Best Buys ... so thats a good start, but it is just a bit of hearsay as of now so we shall see.

but other good news is it looks like Walgreen is investing into charging stations, the one by my house has a station already and two spots reserved for electric vehicles only

Brian H | August 4, 2011

How does Walgreen deal with charging charges? Are the hookups free?

msiano17 | August 4, 2011

Brian H ... actually I do not quite know, I will be by that area again over the next few days and will find out.

Brad Holt | August 12, 2011

I've heard Macy's is rolling out support for EV charging as well, starting in Cali. Last I heard, if you buy something at Macy's they'll give you a voucher at checkout for a free EV charge.

nickjhowe | August 26, 2012

Robert Llewellyn has done a new episode of Fully Charged about the Qualcomm inductive charging system. Looks v. promising. Might be relatively easy (??) for TM to retrofit this into the bottom of a battery pack: Would be great to not have to bother with plugging in every night. I would be happy to take a 5-10% efficiency hit.

jerry3 | August 26, 2012

The maximum hit I would go for is 1% or 2%.

stevenmaifert | August 26, 2012

It works, but is it practical? A few concerns I have:
1) How much does the on-board induction unit weight? The car will be dragging around that weight full time.
2) Time to charge? That video showed the car maxing out at 2.2kw. Assuming the standard 220 UK voltage energizing the base coil, that works out to 10 amps; slower than a standard US household receptacle.
3) Is there a proximity sensor than only energizes the base unit when a car is positioned over it? Otherwise there will be a continuous small power loss much the same as with an appliance charger when the appliance isn't plugged in charging.

ggr | August 26, 2012

Yes, to (3). There is some kind of very low power signaling between the two components. Don't know about the rest.

Superliner | August 26, 2012

The Good Old GM EV1 used inductive technology in it's charging paddle system. there was "no metallic connection" from charger to car. It was done through a magnetic field established when the paddle was inserted into the slot on the cars nose. It was known at the time ("The Car That Could" by Michael Shnayerson). that inductive charging in the form of a simple mat that you park over would work. But a wary public thinking about 240 V @ 50-60 amps ?? what if you step on it? it gets wet? etc. How do you deploy it in the wild??

Hence the paddle inserted in the cars nose. Not really needed but more comfortable to a public who at the time could not see BEV's as being more than a glorified golf cart.

The GM EV-1 was a remarkable vehicle and also was designed from the ground up to be a BEV (no Tesla Model S is not the first)It contained technology available in no other car at the time. It was only hampered by battery tech. of it's day. GenII NIMH EV-1's were pushing 140 + miles of range, in 1999 and established a then record speed "un governed" of 183 mph. One can only imagine where they "GM" would have been with the technology today had they not abandoned it.

This technology has been around for decades. It's been known since the days of Tesla himself that electrons can transfer over magnetic fields from generator to reciever over the air.

bfranks273 | August 26, 2012

Here's the 2014 Infiniti with inductive charging and parking assist

jerry3 | August 26, 2012

Superliner -- But a wary public thinking about 240 V @ 50-60 amps ?? what if you step on it? it gets wet? etc.

This is just a RV plug. The public seems to have no problem with them, and they are in the rain and the dirt all the time. In fact, in the absence of a supercharger or friendly Tesla owner with an HPC, an RV park is the best place to charge because a 50 amp RV plug charges at 40 amps (30 mph) rather than the 24 amps (15 mph) of most ESVEs.

nickjhowe | August 26, 2012

@stevenmaifert - the video says they were only using 2.2kW because of the circuit available at the hotel where they were doing the demo. In the video the Qualcomm guy says it is normally rated at 7kW

Superliner | August 26, 2012

@ jerry3, I was referring to the cordless charging systems for BEV's that are imbedded into or placed on the ground that you simply park your EV over and the current is transferred to the car via magnetic field. Like the system mentioned above by @bfranks273 being "re-invented" by Infiniti

And yes RV parks are a good place to charge up when and if needed.
I helped convert and later bought my first BEV in 1993 (converted 1993 Ford Escort Wagon 120V DC system. Drove that thing for just shy of four years before selling it. Been hooked on BEV's ever since. I've been waiting a long time for the manufacturers to step up.

When the EV-1 was introduced I got on the waiting list but was never able to get a car. Tried to get a Ford Ranger EV, same story demand far exceeded supply. Solectria was converting Geos but they were reluctant to sell to me because my commute at the time was on the bleeding edge of the cars range. A small company called AC Propulsion was producing the T-Zero prototypes which had range and performance on par with Teslas Roadster almost 12 years ago.

Problem was it cost over $200,000 lol!! and only three "I think" were built and it never made it to production.

This day has been a long time coming from my perspective BRING ON THE EV's !!

I'm still kicking around either buying or building a small pickup conversion with perhaps a 144V DC wet cell system to use around town also. after all one DOES need a truck does one not? Lol!

Sorry for rambling !!

Larry Chanin | August 26, 2012

On the road inductive charging applications is where we will see a transformative technology. Large batteries and range anxiety would be a thing of the past.

Standford University is doing some interesting work. Check out this photo that accompanied the article on their work.

Sanford system could allow EVs to recharge from the road, while moving


Timo | August 26, 2012

You need something like 20kW of power to just maintain speed at highways. Sanford experiment reaches half of that. Not enough to remove need of heavy batteries.

Also building and maintaining such roads would be really expensive. I think this is what makes such roads impossible in reality.

I think they are concentrating in wrong area. The place where that could work is in stoplight-limited slow city traffic where energy need is small and crossroads already have gazillion cables and stuff running under them.

electricblue0303 | August 26, 2012

jerry3: why would the RV park 50-amp circuit allow charging up to only 40 amps? I'm planning a road trip with my Model S when it's delivered, and RV parks are my main charging source. I was estimating 45 amps out of the RV park plugs. Anything less than that makes the trip longer than I have time for.

Teoatawki | August 27, 2012

The RV park isn't setting the limit. National electrical code requires wiring be sized to have their maximum continuous load be no more than 80% of the total capacity.

Theresa | August 27, 2012

Also your charger from Tesla is smart enough to know what you are plugged into and also knows the electrical code limits so it will be the factor limiting you to 40 amps. Even though code limits the continuous draw to 40 amps there is nothing in the RV setup that will limit you to only 40 amps other than the breaker tripping from overheating after some time of use. In actuality you can even get over 50 amps for a short time from a 50 amp outlet without the breaker tripping as most operate from the principle of overheating tripping them.

jkirkebo | August 27, 2012

It is as I understand it impossible to get more than 40A from the UMC. However one could buy a HPWC and put a 14-50 plug on it, taking it along. Then you can set whatever charging rate you want on the screen in the car.

ggr | August 27, 2012

... and be liable for burning down the RV park.

dtesla | August 27, 2012

If Model S needs 20 kW to maintain highway speeds and you offset that by 10 kW from the road. You can go 85 kW hours / 10 kW = 8.5 hours (600 miles) at highway speeds between charges... sounds good to me.

jerry3 | August 27, 2012


Teoatawki has it right. You can only run 80% of the rated load if it's continuous. That's also why the 30 amp plugs only give 24 amps.