Wireless charging standards, Qi, Powermat, A4WP, what does it all mean and who will prevail?

We do not know how many people are on the enthusiast bandwagon for wireless charging. Given the rather limited availability on many products, and the fact there is a heated battle between two major standards, consumers are sort of caught in the middle, and it is even more complicated when carriers choose sides too.

So what is the deal with these standards? There are three “big” ones with backing from large technology titans, Alliance for Wireless Power (A4WP), Power Matters Alliance (PMA), and the most well-known Wireless Power Consortium (Qi).


The Alliance for Wireless Power uses a transfer technology called Rezence, based on magnetic resonance, which is basically the opposite of magnetic induction charging used by the competitors. Rezence purports itself to be the “next generation” of wireless charging technology. The magnetic resonance is geared to enable multiple-device charging, better charging range through layers (as in, through materials like books, clothing), to distances ranging a few feet, and operation in the presence of other metallic objects in what A4WP calls “real world” situations (kitchen appliances, keys, etc.).

Rezence looks to leverage existing short-range communication, particularly Bluetooth 4.0 in pursuit of “smart charging zones” and minimizing manufacturing hardware requirements. As it is right now, A4WP is really a specification, not a standard, as a standards organization has not recognized A4WP for regional acceptance.

Out of the three, A4WP is the underdog, despite having membership from companies like Qualcomm, MediaTek, Intel, LG, HTC, Samsung, and Deutsche Telekom, to name a few out of a list of roughly 100 companies. The applications that A4WP are more commercial in nature where products are then consumerized for use. It is highly unlikely we will see any smartphone with wireless charging that uses this specification. That would explain why A4WP has agreed to merge its charging specification with Power Matters Alliance.

Power Matters Alliance

If you know the Powermat, then you know PMA. Founded in 2012, this organization made headlines recently when Starbucks announced that it would begin incorporating PMA wireless charging across all 8,000 or so stores in the United States over the next 18 months.

The corporate membership in PMA is a little bigger than A4WP, and the solutions are more consumer oriented. Notably, AT&T is an industry member of PMA. The result for consumers, at least in the US, has been that devices that would otherwise have a competing wireless charging standard enabled, have had it removed in AT&T’s case. The carrier has then providing wireless charging cases at an extra cost.

As it is right now, we are only aware of two devices in the US market that natively support PMA wireless charging, the Kyocera Hydro VIBE and the Hydro Icon, both mid-range Android devices that also happen to be water resistant.

Where PMA is gaining ground is in a “pull strategy,” where companies are building in support for the standard with the aim of creating a de-facto consumer demand. This is being pursued through measures similar to what Starbucks is doing. DuPont will be doing something similar for surface products it makes for the home (kitchen counters, etc).

So, while it could be argued that PMA is to wireless charging what Betamax and HD-DVD were to VHS video tapes and Blu-Ray, there is enough muscle behind PMA to continue creating a disturbance in the force that is Qi.

Qi - Wireless Power Consortium

Meet the 800 pound gorilla of wireless charging, Qi. Backed by more than 200 industry members, including Verizon, Nokia, and LG, Qi is the standard that so far has the widest global distribution and penetration, from charging plates to automotive cradles.

From an industry perspective, Qi is not any less capable than PMA from a “connected world” standpoint. However, the consortium is going tit-for-tat with PMA when it comes to pushing infrastructure initiatives. Qi also has strong end-user backing.

Interestingly, Powermat, one of the earliest wireless charging products, was part of the Wireless Power Consortium, and was part of the standardization of the Qi format. Unfortunately, there was a difference of opinion over the adoption rate of wireless charging, so Powermat left the WPC and started the Power Matters Alliance, and here we are with what we have.

What is the difference?

When it comes to Qi and PMA, they both use inductive charging, but the differences are that Qi’s wavelength is 100-205kHz and PMA’s is 277-357kHz. Otherwise, the method itself is the same. The rest of the differences have to do with the driving forces behind each standard.

Another factor is that PMA is seen as having an edge when it comes to the “intelligence” in creating a mesh of wireless charging points. Then, merchants are able to manage how, and who, can use wireless charging, as well as develop applications that may be used to help find places to charge devices.

Who is going to win this?

Unlike the other standards battles we have seen unfold in the past, Betamax losing to VHS, HD-DVD losing to Blu-Ray, and HomeRF losing to Wi-Fi, the outcome in this drama is not certain. Given the lead and backing that the Wireless Power Consortium’s Qi has, it seems easy to give them the edge. However, PMA does not have an empty bench, and just as Starbucks gave Wi-Fi a visible edge years ago, the association sees the coffee shop’s adoption of its standard as a similar development. Moreover, PMA and A4WP agreeing to merge specifications lends a more collaborative effort which could generate more momentum down the road.

Who loses in all this?

In the near term, it will be the consumer that gets caught in the crossfire. However, major manufacturers like Samsung, Sony, and LG, are members of all the industry groups. Whether that is to hedge bets, or serve all the consumers is anyone’s guess, but both hold weight.

From a smartphone or tablet perspective, it can certainly be argued that carrier involvement does not help consumers or manufacturers. AT&T supports PMA, Verizon is backing Qi, as is Nokia. So devices being made by Nokia have to be altered specifically for AT&T, leaving users with less attractive options if they want to use wireless charging.

Kyocera’s support of PMA does not mean anything in the current environment, as the manufacturer’s market share does not register in the United States. Will PMA’s strategy work? That remains to be seen. If we see manufacturers start making gear across both standards, then that would be a feather in PMA’s cap. How such a development impact Qi is too difficult to speculate on.

It seems fairly apparent that we are going to be wireless well beyond communications in the foreseeable future. The question remains to what extent we, as consumers, will embrace it. Do you see your future as totally cable free?



1. fzacek

Posts: 2486; Member since: Jan 26, 2014

Does the higher wavelength of PMA make it more powerful and faster charging or less powerful and slower charging?

2. joey_sfb

Posts: 6794; Member since: Mar 29, 2012

That's lazy to plug in a cable.

16. reckless562

Posts: 1153; Member since: Sep 09, 2013

not about lazy, its about True wirelessness and product integration. with true wireless charging tech the possibilites are ENDLESS!!! imagine, any pants or shirt ur wearing be able to be a charging zone in ur pocket, n charge ur clothing item at ur desk or car while driving....... of course a leap in BATTERY (come on already nerds!!!!!) technology would put this stuff on the backburner for a while

3. amiaq

Posts: 509; Member since: Jun 30, 2012

I see so much potential in wireless charging especially commercial application like Starbuck.

4. engineer-1701d unregistered

The bigger thing here is no port means better water proofing. Or mag charging like ibook

10. joey_sfb

Posts: 6794; Member since: Mar 29, 2012

Good point on the water proofing. Still too many competing standards for wide spread adoption. Cable still has the speed advantage.

13. DonShock

Posts: 19; Member since: Jan 06, 2012

Another issue is device longevity. Constantly plugging and unplugging a charging cable makes the charging connection the most susceptible to wear and damage. Especially now that the same port is used for both data and charging. A broken port is a frequent repair issue. Minimizing port use by wireless charging makes as much sense as using cases and screen protectors if your goal is keeping your device functioning.

15. joey_sfb

Posts: 6794; Member since: Mar 29, 2012

Samsung microUSB cable has tiny clips that hook into place. Its offer stronger connection and has a durable build compare with generic microUSB cable. Check it out.

5. sam_tek

Posts: 105; Member since: Feb 18, 2011

Rezence sounds the coolest. Especially when I can charge my device not by placing it on a mat at the exact place for the charge to happen (pain in the butt imo - i don't use mine as much for my Nexus 7 II), but by just physically being in the environment of the charge! And I like to back the underdogs! :D Also....nice article Maxwell! Very informative.

7. 0xFFFF

Posts: 3806; Member since: Apr 16, 2014

Rezence technology has a lot of promise and is being looked at for charging electric cars. Qi had its chance and has failed to achieve critical mass, IMO mainly because of price. Maybe PMA will do a better job and pull wireless charging into the mainstream.

6. kaikuheadhunterz

Posts: 1157; Member since: Jul 18, 2013

From what I've read, A4WP seems much better than the other two

8. chocowii

Posts: 478; Member since: Jan 30, 2014

Conductive charging is all we need. When a wireless charger is put on a table and you can charge anywhere on the table not on the spot where the charger is. We get that wireless charging is great just make it more usable...

9. E34V8

Posts: 109; Member since: Dec 16, 2011

This article makes it sound like wireless charging is something new and rarely used. But it's not. In fact, many users already charge their phones with Qi chargers. There are so many Android smartphones that support it. I charge my Nexus 5 with a Qi charger. It's super connivent.

11. muhsen

Posts: 281; Member since: Jun 07, 2012

Well, given that Nokia was the first to promote and is still almost the only one pushing the wireless charging thingy, it's probably the Qi standard that will win, they have the highest volume sales for wireless charging capable phones ( All lumias from lumia 720 and upwards with the exception of the lumia 1320). LG also provides its flagships and nexus devices with Qi wireless charging but they are not promoting the feature that much ( or at all).

12. RandomUsername

Posts: 808; Member since: Oct 29, 2013

I prefer a magnetic dock like for the Xperia Z series. It's just as easy and much more efficient.

14. jojon

Posts: 435; Member since: Feb 11, 2014

I have wireless charging on my Lumia 925 and i have to tell you once you have it there is no going back..ever. It is now where you leave yr phone when not in use and every time you pick it up it's fully charged. The wall charger now lives in the car for when you travel. If you have a Lumia 720 and up, do yourself a favour, fantastic.

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