Apple Inc's embrace of wireless charging for its new Watch may be a defining moment for a technology that's languished for years amid competing standards and consumer confusion.
Supporters of wireless charging see a future where people no longer worry about topping up their gadgets; are free from tangled power cords and low-battery warnings and where terms like "outlet" and "plugged in" will be as anachronistic as "dialling" a phone.
Users seem to like the idea too: in a recent survey by technology consultancy IHS, 83 per cent were interested in wireless charging; in China, the figure was 91 per cent.
But, while the technology is largely there to do this, competition to set a global standard is getting in the way of delivery. It's reminiscent of the Betamax vs VHS videotape wars of three or four decades ago, or the more recent battle between Blu-ray and HD DVD for supremacy in high definition optical disc format.
For now, there are three alliances, but not much to show. Last year, fewer than 20 million phones were shipped with wireless charging built in, according to IHS - less than 2 per cent of the billion smartphones shipped around the world.
"There are a lot of bees around the hive," said Omri Lachman, CEO of Humavox, an Israeli start-up with its own wireless charging technology. "Up to now we've not seen a mass aggregation of wireless charging in devices. There's a good reason for that: three standards for the same form of technology."
While users clearly see wireless charging - where mobiles, tablets and other devices are charged by laying them on a mat or other surface - as a natural next step, some industry leaders have cautioned that having to still plug in the charging device may prove fiddly for some.
"Having to create another device you have to plug into the wall is actually, for most situations, more complicated," Apple senior vice president Phil Schiller said just two years ago.
Beam me up
Maybe, but others say the wireless vision remains compelling. "Look at Star Trek," says Geoff Gordon of the Alliance for Wireless Power (A4WP), one of the three competing alliances.
"They never talk about their batteries dying on any of their devices. If you look far enough into the future we're looking at a world where you don't even think about power."
But to catch on, wireless charging has to work seamlessly. That means a user can easily find a wireless charging zone and not have to worry whether their device is compatible, or properly connected or even secure from theft.
Intel Corp, a member of A4WP along with the likes of Samsung Electronics and Qualcomm Inc, says wireless charging is a lot like wireless computing. Just as the world has largely ditched network cables for wireless hotspots, so we will leave chargers and cables at home as we'll never be far from a charging pad.
But getting there, the chipmaker argues, will require someone with its clout to set the global standard for wireless technology. "History will tell you it's what it takes to get mainstream lift-off," said Intel's Leighton Phillips.
Among the competing standards, A4WP uses something called magnetic resonance, while the Wireless Power Consortium (WPC) - which includes tech names such as Nokia and Philips - champions its Qi standard using inductive charging, a method which is also used by the Power Matters Alliance (PMA).
They are all variations of the same technology: a coil inside the device picks up an electrical charge from a transmitter coil in the charging surface. Apple, which sits outside the alliances, appears to have used a version of induction charging in its Watch, further muddying the waters.
$8.5 billion market
Sparring in a battle for leadership in a market that IHS reckons will be worth $8.5 billion by 2018 - as the technology is incorporated into devices, furniture, cars, restaurants - the alliances fling accusations at one another.
The WPC accuses its rivals of trying "to benefit from intellectual property they think they own," in the words of WPC vice president for market development John Perzow, instead of "what benefits the consumer."
The WPC's Qi brand is the only one to have made any real headway on the market, doubling its annual shipments to 20 million devices last year. The PMA has a couple of products out, while the first devices carrying the A4WP's Rezence brand are expected to be shipped this year.
A4WP supporters say the WPC has had its chance and blown it. "Very quickly the momentum behind A4WP will dwarf anything that Qi has accomplished," says Alex Gruzen, CEO of U.S.-based WiTricity.
The PMA, meanwhile, has focused less on the hardware and more on the application programming interface that would allow others to connect to it. Its main backers are companies like Procter & Gamble and Starbucks Corp, which promises to roll out charging surfaces in its U.S. outlets by the end of next year.
The groups all agree on one thing: squabbling over standards has kept smartphone manufacturers, furniture designers and car makers from building wireless charging technology into their products as much as they might if the technology's future were clearer.
The Jeep Cherokee, for example, includes a wireless charging pad, and Cadillac has announced plans to add wireless charging in 2015 models - but drivers will only be able to use the feature if they have compatible phones.
There are signs of progress: the A4WP and the PMA in February agreed to ensure their two standards work well together.
But for wireless charging to take off, Intel says, it not only needs compatible devices and charging mats in homes and offices, but also a broader public infrastructure - coffee shops, hotels, malls.
"The vision we have and that Starbucks has is that it becomes part of the slipstream of your life," says Powermat president Daniel Schreiber. "How do we make power come to you rather than have you think about power?"
There are other issues. One is that the technology still needs to be easier to use. In some cases, a device can't just be dropped anyhow onto a charging pad - it needs to be aligned or it either won't charge, or will charge more slowly.
Also, fitting charging coils into devices isn't as simple as it may sound. "Coils have a physical limitation that won't change with size," said Humavox's Lachman. "A lot of people have been trying to fit that into the device."
"All the companies are working around the clock to figure out how to pull in that technology and make sure it works," says Pavan Pudipeddi, CEO of PowerSquare, which in July launched a charging pad using Qi which allows users to recharge multiple devices.
Pudipeddi welcomed the launch of Apple's Watch with wireless charging. "Others will feed off that and it's good for the technology in general," he said.
Meanwhile, the dithering over an industry standard is opening up opportunities for others.
Some companies like uBeam, for example, use ultrasound, converting electricity to sound and sending that over the air as ultrasound. Others, like Humavox, use radio frequencies, where the coils are replaced by antennae.
"Our decision to build this technology from the ground up is proving the right choice," said Lachman. "Wireless charging has been out there for five years and nothing's happening."