Josh Valcarcel/WIRED



Wireless charging sounds nice, doesn't it? No more ports. No more cords. Just plop your smartphone (or, someday, something even bigger!) down on a charging pad—or better yet, on a table that has wireless charging pads built right in.

As far as futures go, it's a pleasant one. And some of us are already living in it; 16 percent of respondents to a recent IHS study say they use wireless charging every day. When you consider that three in four percent of consumers are aware that wireless charging exists, though, that number suddenly seems pretty small. Who would knowingly turn down that kind of magic, and why?

A lot of reasons, it turns, out, but mostly this one: There are too many standards, and no clear path to resolve them.

Tangled Wireless

In January, two major wireless charging powers—the Alliance for Wireless Power (A4WP) and Power Matters Alliance (PWA)—announced that they would join forces. In July, that union became official. Last week, the happy couple decided on its new name: AirFuel Alliance, an organization whose 190 member companies are “dedicated to building a global wireless charging ecosystem.”

It sounds like progress, and it is, in a sense. The only catch is that the tie-up doesn’t really mean anything, at least not technologically, because A4WP and PMA have backed different standards (called “Rezence” and “PMA,” respectively), and combining forces hasn’t changed that. “It’s a great sign that people want to simplify wireless charging for consumers,” says IHS analyst David Green, “but it doesn’t instantly make the two standards interoperable.”

The fundamental differences between the two will make interoperability difficult to achieve.

PMA, which you might have seen in the form of a Duracell Powermat at Starbucks locations sprinkled throughout the country, relies on magnetic induction. There’s a lot of science at work that you can read about in more depth here, but it basically depends on the alignment of a transmitter coil (typically on a charging pad) and receiving coil (in the device). An alternating magnetic field generated by the transmitter coil is converted to electrical current by the receiver, and presto! Your battery fills.

Rezence, meanwhile, deploys magnetic resonance charging, taking a principle that’s been in play since Nicola Tesla and applying it to powering smartphones. It’s similar to magnetic induction, in that it relies on the interplay of coils, but trades power transfer rates for the added convenience of not needing to perfectly align transmitter and receiver. In fact, Intel, a prominent Rezence supporter, showed off charging bowl nearly two years ago. Just drop your phone in and go:

Housing those two technologies under one roof is promising start, but bringing them together in a consumer product is another issue altogether. "We have a concerted effort looking at multi-mode wireless charging," says Geoff Gordon, co-chair of marketing for AirFuel. "That would be implemented either on the receiver side or the transmitter side, and it would function on both AirFuel inductive and AirFuel resonance."

The good news is, they've got some time to figure a multi-mode system out. In fact, a company called NuCurrent has worked with Broadcom to make a functional multi-mode antenna that could make smartphones truly agnostic. The bad news is, Rezence products still haven't made it to market yet.

Oh, and more bad news: Not only is AirFuel not compatible with itself, it's positioned against incumbent WPC, which promotes another standard altogether, called Qi (pronounced chee), and has since 2008.

Qi's technology is very similar to PMA's; it also uses a tightly coupled inductive solution, though at a different frequency. But wait! Qi added resonance charging to its spec last year, promising backwards compatibility for Qi receiver devices (smartphones, tablets, etc.) sold in the last three years.

So to summarize: AirFuel is PMA and Rezence, which is inductive and resonant, respectively, but Rezence doesn’t yet exist. Qi offers inductive and resonant charging in the same standard, neither of which is compatible with either of AirFuel's.

Please take a moment to let your head stop spinning. Or don’t! Because support for the technology is as muddled as the standards themselves. Starbucks supports PMA, as we’ve said. So does Madison Square Garden. But Ikea sells furniture with Qi built in. Samsung sells line of monitors that double as Qi charging stations. AT&T's a PMA shop. Verizon is in Qi's corner. And on and on and on.

"At what point does it get confusing? I have to say probably we're at that point, if you’ve been following it," says WPC VP of market development John Perzow. "But for consumers, it’s probably not."

That sounds like a contradiction, but it's not quite when you consider most consumers simply haven't had the chance yet to be confused. Remember, only 16 percent of them are using wireless charging every day to begin with, and they haven't yet been confronted with the added complications of Rezence. Those who do use wireless charging likely just bought a compatible charging pad along with whatever smartphone or wearable they have. Think of the Apple Watch's dedicated charging station.

The real question, then, is how do you increase the ranks of the wireless charging faithful without increasing befuddlement?

A La Multi-Mode

It's true that a very small percentage of smartphones offer wireless charging today. It's also true that the most prominent one to do so, the Samsung Galaxy S6, offers a sort of best-case scenario for AirFuel, WPC, and consumers. Thanks in part to a Broadcom chip that can toggle between wireless charging standards in the background, the Galaxy S6 works with both PMA and Qi.

"Right now, if a customer has their Samsung Galaxy S6 and they find a charger on the table in their local coffee house, it will either be a Qi or PMA charger, and everything will work," explains Green. "Customers don’t understand or care about different standards, they just want to know 'I have wireless charging and it works.'"

That's one solution, though it's best to think of it as more of a band-aid. A so-called dual-mode receiver (read: smartphone) places the onus on hardware manufacturers to bridge an unnecessary gap, at their own expense. That doesn't seem viable in the long run, any more than if the HD-DVD and Blu-Ray rivalry had been settled by Sony, Toshiba, et al. deciding to make players that were compatible with both types of disc.

Green notes that the cost difference between single-mode and dual-mode (which is to say, supporting both PMA and Qi versus just one or the other) to smartphone manufacturers is negligible, in the neighborhood of 5 percent. That, at least, is encouraging for the next few years, while PMA and Qi still prevail. Once Rezence enters the frame, the plot complicates. Multi-mode handsets are much more expensive to produce than single or dual-mode; IHS forecasts that it will be another four years before even a third percent of receivers can handle both inductive and resonant technologies.

'At what point does it get confusing? I have to say probably we’re at that point, if you’ve been following it.' WPC's John Perzow

Besides which, not all smartphone manufacturers are rushing toward wireless. Google's Nexus line has turned the opposite direction: After several generations of Qi support, the latest flagship Android devices have ditched wireless charging altogether. The stated reasons? A USB-C port provides quicker charging than wireless, allows for a thinner build, and is more convenient than microUSB.

A more sustainable future may be to focus not on the smartphones and wearables and other devices, but on multi-mode transmitters, the type which Gordon alluded AirFuel was working, and Qi has already demonstrated. "We're definitely making plans for supporting multiple technologies," says AirFuel's Gordon. "Consumers don't want to have to take a logo and match it up with the logo on the pad they're looking at. They just want them drop their phone and have it charge. That's what we want as well."

That's what we’re really talking about, right? Go to a restaurant coffee shop, plop your smartphone on the table, and not worry whether it’ll be fully charged by the time you’re done. Then again, that doesn’t seem likely as long as Qi and AirFuel are still fighting it out. And how many restaurants and coffee shops are going to place that kind of bet this early?

The Infrastructure and the Egg

"There are some people waiting on the sidelines," says Gordon of the infrastructure issue. "There others who are making smaller capital investments who will make broader decisions once this really happens."

You can't blame them. Consumers are used to rotating through their phones or wearables every two years or so, and having to upgrade a peripheral along with that is increasingly part of the bargain; just ask anyone with a rat king of obsolete 30-pin cables in their junk drawer.

Outfitting a piece of furniture, or an outdoor installation, or a car with wireless charging, though, is a much deeper investment. One that’s also more expensive to retrofit, in case you end up backing the wrong standard.

This matters, because seamless wireless charging in public places is arguably more important to the technology’s future than having it at home.

"Wireless-charging-enabled furniture in restaurants will never outsell standalone transmitters," wrote Green in a recent white paper, "but has a much higher impact on consumer awareness… Customers may charge [a mobile phone] at home, but the use-case is arguably more about the freedom to charge everywhere they go—at home, in the office, and particularly in public places. Customers will very quickly expect this use-case for any mobile phone that is enabled with wireless charging—they do not care for the different standards, only that wireless charging just works."

Any Rezence product you buy in the future, though, won’t work on your Ikea furniture or those Starbucks tables or anywhere else that's already made a significant investment in helping wireless charging realize its true potential. In fact, the first product of any kind that will work on either existing standard is the Samsung Galaxy S6.

And so we’'e stuck again. Manufacturers won't produce the devices until consumers demand them. Consumers won't demand them until they see how well it works in public places. Public places won't commit to them until manufacturers settle on a standard.

It sounds hopeless, but there's at least some good news... if you look long enough down the road.

Forward Charge

In one sense, it's probably for the best that there hasn’t been a major infrastructural investment in wireless charging technology yet. The current inductive standards are convenient, but also slow and fickle, and limited to smaller devices. They don't deserve much more than a stopgap, like dual-mode, to keep early adopters supported until they're finally put out to pasture. Those battles are largely moot.

The future, however long it takes to get there, belongs to resonance, which is far more accommodating. That still doesn't solve the Qi versus AirFuel fuss. But while two organizations stand in opposition, it turns out there’s not much separating them after all.

"Almost every member of the newly formed AirFuel is a member of WPC," says WPC's Pezow. "For them, making the switch is nothing. It's not a steep technology curve for an organization to learn. Also the spec is free. It's very easy, technically and monetarily, to adopt the Qi standard."

That means, of course, that the reverse is also true; many WPC members, including heavy hitters like Qualcomm, Samsung, and Sony, are also card-carrying AirFuelists. And while there are some prominent holdouts on both sides (Intel is Airfuel-only; Verizon is strictly WPC), there’s enough cross-pollination that it wouldn’t be as painful as it might seem to for the industry to get behind one or the other when the time comes.

In the meantime, wireless charging has time to refine itself. "Manufacturers are already developing higher power for wireless charging," Green says, "both for mobile phone quick charge, and for applications such as laptops."

That’s the wireless charging you want, the wireless charging that's worth waiting for. It'll just take a few more years of confusion—and yet another pointless standards war—to get there. Until then, you might want to just follow Google's lead and hold off on wireless charging altogether. USB-C's pretty darn nice—and you never have to worry if it works.