One of my goals for CES was to see if wireless charging technology is ready for mainstream consumer adoption. The answer is yes if you’re making contact with a charging pad, but only maybe if you’re not.
Charging pads, of one kind or another, were easy to find at CES. Near field charging – putting a gizmo in direct contact with a wireless charging device – appears to be a maturing technology. Although the Qi standard is gaining – Samsung, LG and Apple support it in some of their models – compatibility is still an issue. There’s no universal solution yet for wirelessly charging your smartphone or wearable device, in the same way that pretty much anything with a wire can plug into a USB outlet. That’s more of an issue for public spaces, though. Consumers can buy what they need to do what they want.
Wireless charging at a distance, though, is more challenging. I saw two companies that claimed to have technology that would allow contactless charging. The most aggressive claim came from Powercast, a Pittsburgh, Pennsylvania-based company that says its FCC-approved technology can deliver upwards of 100 milliwatts – enough for many wearables, if not for a smartphone – at distances of 1 to 3 feet. Very low power, Internet-of-things devices can be charged up to 80 feet away, according to company staff.
I’m cautious about accepting wireless charging performance claims at face value, mainly because of the second company, Energous. Two years ago, it exhibited a prototype that company executives said would work at distances up to 15 feet. And maybe it would, although I didn’t see them actually do it. It ended up on the scrap heap because the company couldn’t get technical approval from the FCC. It used the same 5 GHz band as WiFi devices, and blasting out multiple watts of radio frequency energy into that spectrum would be sure to interfere with data transmissions.
Energous has backed off from those claims, though. The company recently received FCC approval for technology that also has a 3-foot range. It hasn’t been rolled into a product yet, so there was no demo or prototype on display at CES, but company staff at the show expect that manufacturers will adopt the technology and integrate it into products by the end of the year.
Closer to reality.
Energous Corporation is walking back claims of wirelessly charging batteries from across the room, but is moving ahead with products that charge on simple contact, without having to plug anything in. That kind of technology is reasonably well established – it’s a common enough demo to see at CES, for example – but the solutions on offer are still fiddly in nature and there’s no generally accepted standard yet.
Last year, at Pepcom’s Mobile Focus event in San Francisco, Energous had a gizmo generally the size and shape of a high end audio speaker on its exhibit table, that a spokesman said could deliver 4 watts of electrical to a suitably equipped device 15 feet away, and 16 watts at five feet. Energous was back at this year’s Mobile Focus with a less aggressive pitch and a different looking power beaming box that was described as a mock-up. It’s still effective up to 15 feet, I was told, but at “trickle charge” power levels. And it’s still not in production, or approved by the FCC, which has to sign off on anything that emits radio frequency radiation, regardless of purpose.
On the other hand, Energous was also showing a (now) FCC-approved contact-based charging device, called the Miniature WattUp, that’s essentially a dongle that you can plug into a USB port and then rest a small rechargeable device on top. So far, no consumer electronics manufacturers have adopted Energous’ technology – contact-based or otherwise – but at least it has a marketable product and reasonable hopes of seeing it in production next year.
Big charger with a small beam.
The easiest way to charge a wearable gizmo is to do it while you’re wearing it. Taking off a fitness monitor, say, every night is a fast route to leaving it behind every morning. Energous Corporation has a way to make that happen.
The company demoed its short range wireless charging technology at Pepcom’s Mobile Focus event in San Francisco in May. The idea is to use 5 GHz WiFi transmissions, pinpoint focused by a Bluetooth steering beacon, to charge handheld devices. The two questions that pop to mind are 1. is it safe and 2. will anyone believe it?
The answer to the first question is yes, according to George Holmes, a marketing executive for the company. And he’s probably right, given the low heat levels involved and the fact that, thermal effects aside, there’s no rational basis for believing that radio waves cause any harm to living things. That said, the FCC hasn’t signed off on the technology, from either a safety or interference perspective.
Holmes believes the rational segment of the market is all Energous needs. “There are people who will use this because it’ll make their lives more convenient and some who won’t”, Holmes said. “I’ll never sell to those who won’t”.
The claimed charging capability is pretty robust, ranging from 16 watts at 5 feet away to 4 watts – enough for most mobile devices – at 15 feet. Up to 12 devices can be charged at once. The secret sauce behind the product is the antenna steering technology that can focus power on a small point, and follow it as it moves.