SAE Agrees On J2954 Wireless Charging Standard, Test Stations Will Ensure Interoperability

JAN 31 2017 BY MARK KANE 25

SAE J2954 Wireless Charging - Timing Plan

SAE J2954 Wireless Charging – Timing Plan

SAE International is one step closer to fully releasing the SAE J2954 wireless charging standard.

Soul EV wireless charging concept

Soul EV wireless charging concept

The latest update is on the operation of test stations for the future base standards – currently 3.7 and 7.7 kW power levels, which will allow automakers to design and sell wireless systems today with future compatibility being assured.

Taskforce members, which include carmakers, Tier 1 suppliers, and technology providers from around the world, will then decide on the higher power standards: specifically on the 11 kW level later this year, with the standard is to be published in 2018.

“The Taskforce members have agreed on specifications for the SAE J2954™ Test Stations, which automakers will use as a basis to develop their wireless charging systems, and to verify that they will interoperate with charging systems and vehicles sold by other makers.  The Taskforce agreed that the WPT1 (3.7 kW) circular coil system and the WPT2 (7.7 kW) circular coil system will be in the Test Stations used to test products developed by car makers, Tier 1 suppliers, and charging infrastructure suppliers to confirm SAE J2954™ compatibility.  These wireless charging systems charge at the same rate that existing Level 1 and Level 2 wired chargers operate.”

BMW i3 with 7.2 kW Plugless wireless charging

BMW i3 with 7.2 kW Plugless wireless charging

“Earlier in 2016, SAE International performed bench testing of these systems at the US Department of Energy’s Idaho National Laboratory and TDK to confirm that charging rates, efficiency, and emissions can meet regulatory guidelines and consumer expectations.  Testing results validated interoperability between different coils (both circular and DD) with high efficiency. This enabled the RP SAE J2954™ test station to have a greater degree of freedom to prove interoperability with other topologies with newly established interoperability criteria. The goal is to standardize key elements but at the same time “keep the door open” for innovations in wireless automated charging in the future.

The consensus reached by the Taskforce enables carmakers the freedom to design the components for their own vehicles based on their preference for coil topology and power electronics design, while assuring that such systems will interoperate with the charging source that is deployed on the ground.

In 2017, the Taskforce will decide on other aspects of the standard, including standardization for wireless charging systems capable of WPT3 (11 kW) charge rates.  The specifications of the SAE Test Station and procedures for validation for both the vehicle and infrastructure chargers will be defined in the SAE J2954™ Recommended Practice to be published later this year.  The final SAE J2954™ Standard is to be published in 2018 based on actual vehicle test data.”

The Mercedes S550e (S500e internationally) is the first production EV to get wireless charging this year (as an option)

The Mercedes S550e (S500e internationally) is the first production EV to get wireless charging this year (as an option)

Jesse Schneider, chairman of the Taskforce said:

“Charging your vehicle should be as simple as parking it and walking away—and wireless charging with SAE J2954™ enables that freedom and convenience to do this automatically. Automakers believe that wireless charging can greatly help to make both electrified and autonomous vehicle mainstream, and they have been active supporters of our standardization efforts.

Reaching a decision for a common J2954™ RP test station, equipped with circular topology, provides automakers with the technical direction for their wireless charging system design, development and production release plans to meet industry compatibility, interoperability and performance standards.   It is a major step forward for the industry.”

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25 Comments on "SAE Agrees On J2954 Wireless Charging Standard, Test Stations Will Ensure Interoperability"

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This and 30-40 miles of range can’t see why anyone would buy an ICE only car.

Agreed. I can understand why people are still hesitant to go full electric. But there is no good reason not to AT LEAST go PHEV.


Meanwhile, automakers are still investing lots of money in hydrogen while battery cell costs are coming down to levels supporting mass market proliferation.

PHEV’s, and even BEV’s, are viable today.

You are a bit out of touch with reality, unless by “mass market” you mean some gated community of millionaires aiming for bragging rights with new P100D toy. $100/kWh at Li-Ion cell level is still a dream, even if achievable in few years. When achieved, it would mean $10,000 just for cost of goods just for cells alone for 100 kWh 300 mile car. Add R&D, manufacturing, warranties, retail and so on, and you are well over average new car MSRP just for with cells alone, but you also need to pack cells and make the rest of the car in addition.

On the top of this it would be still restricted range and would not match cars that can be refueled in 3 minutes in any time, summer peak in South when grid can’t cope, or January morning in North at -25 C when Li-Ion range plummets on floor, and would not be usable by half of the world population that doesn’t even have such option to charge at home. These are the reasons mainstream automakers invest into some more universal and cheaper technologies in addition, not just Li-Ion exclusively.

Why does it have to be a Tesla P100D?

Your rant doesn’t work when considering PHEVs like the Volt, or Outlander PHEV.

Discussion about PHEVs . . . so he rants about P100D. What?

That’s terrible trolling-fu.

Yes. Even Sven wouldn’t make such a weak argument. 😀


Only zzzzzzzzzz is enough of an anti-EV troll to try the “Oh, but charging your EV will collapse the grid!” argument. That’s such a tired old cliche that it’s #2 on the list of “The EV-Hater’s Guide to Hating Electric Cars” (link below).

Even Sven knows better than to try such obvious B.S.

The article is about wireless charging, they show a Soul EV and i3 EV, so it is not just about PHEVs.

My only reason for no PHEV is that there’s more complexity and 2 systems to worry about. Plus, the vast majority of PHEVs are driven mainly in ICE mode due to to small BEV range. So they’re not really contributin that much to lowering GHG emissions in the long run. Pure BEV is the only way to go if it fits your lifestyle and needs.

– the ICE-only car costs a lot less
– it’s harder to have a wireless charging solution than a wired charging solution

Aside from the possibility for taxi ranks, wireless charging is essentially a luxury charging option.

– the ICE-only car costs a lot less
Not really. PHEV are now cheapest option in some mid-size cars. Small ICE are still cheaper than small BEV though

– it’s harder to have a wireless charging solution than a wired charging solution
Not really. The wired solution has to account for wear and tear, and user error.

The $7500 tax-credit can largely cover the cost increase of a PHEV over an ICE car. So why get the ICE?

Makes no sense to me.

It also makes no sense to me that so many car makers didn’t go with a full 16KWH battery but I guess they are now fixing that mistake with newer models.

Those charge rates are pretty slow but that’s fine. This kind of charging should only be used at work parking spots or home where you plan to park for a long period of time and thus the slow rate doesn’t matter.

Personally, I’m not a fan of wireless charging due to the wasted energy but if the technology helps people buy an EV instead of ICE then I’m all for it as an option for many.

I kind of agree on the wasted energy part. It’s fine for my 4Wh cell phone charge that ends up using 5Wh instead, but even just an optimistic 10% wasted on 10kWh charge per day adds up. That works out to about 10 cents per plug in assuming I’m driving about 30 miles a day. I think I’ll save my dime every day, it’s just not that hard to plug in. But this clearly has use cases that make sense outside of a garage, and it might just be the tipping point for some – so I’m all for it.

As a side point, upgrading my 2011 Volt at 93mpge on electric to a 2017 at 106 mpge on electric would be a 14% efficiency improvement – about the same as the real-world losses on wireless charging. So I guess if I get a 2017 Volt and use wireless charging, I can do so guilt free because my miles per kWh from the electrical panel will be about the same! 🙂

Considering how much money I save by not buying gasoline, 10cents/day is meaningless. Also, time is money. My EV is parked outside, and today I had to mess around with a wet/snowy/dirty cable. Nothing like getting black marks on your pants in the morning. It would have been nice to just get in my car & drive away. Same for plugging in tonight when I get home.

There’s also the case for elderly w/Rheumatoid Arthritis, or other ailments. And don’t forget the disabled. And there is a case for autonomous cars that park themselves. Now they can also charge themselves.

Yes, but in case of snow or ice, this set up is no good, because it with get ripped off by the snowplow, or if snow turn to ice on top of a unit after being melt by the dissipated heat, you might not be able to get your fender over it.

It would have to be buried hard into the ground.

It’s not cheap!

Nothing is perfect.

Still, if it’s all it take for the gogo to go EV, well, I’ll close my eye take a deep breath and pretend I have seen nothing.


I don’t think there’s any question that if — or more likely, when — people start installing wireless chargers in on-the-street parking places, the charger will have to be buried flush with the pavement, or perhaps even buried under it, so that even heavy vehicles (and snow plows) driving over it won’t damage the charger.

I’ve been wanting wireless for a couple years now. For no other reason than coolness.

Now that there is finally a standard, it’s looking better.

I’ve had mine for 3 years now, Loboc.
Why you’re waiting for a universal system is beyond me. Plugless is great for home use so you just plug-in on road trips is all.
Why wait? Get Plugless for your Volt, you wont look back.

On your system, is orientation important? Can you park at any angle over the coil and it will charge? Say one day you back over it, and another day you pull forward over it.

I’m with Kdawg here. Please give us a report of how you use it, preferably with a list of what’s good and what’s bad about the system.

So, it sounds like they will allow custom topology while having a standard for the power outlet.

1.) This will make a thousand mechanically incompatible standards flourish.

Basically, don’t count on wireless charging to come into the mainstream anytime soon. They’ve doomed it.