Wireless charging reaches beyond the charging pad, finally

Powercast has some good news about juicing your headphones, smartwatch or fitness band. Your phone? That gets more complicated.

Powercast's PowerSpot transmitter (top) will charge wireless devices over the air.

Step away from the charging pad.

Powercast said Tuesday that it's won FCC approval for its PowerSpot transmitter, which can deliver over-the-air charging to electronic devices two or more feet away and, in some cases, as far as 80 feet (24 meters). The idea is that charging certain devices could work a little like Wi-Fi does: The devices just have to be in the vicinity, rather than plugged in or plopped down in a particular spot.

The biggest beneficiaries for now will likely be keyboards, remote controls, certain wearables and especially low-power devices like home automation sensors.

You're hoping for wireless phone charging? That gets a little more complicated.

The company plans to show off prototypes of its 3-watt PowerSpot two weeks from now at CES, the consumer electronics extravaganza in Las Vegas that sets the stage for the coming year in gadgets.

Up to this point, wireless charging has been a very short-range thing, based on two main standards -- Qi and Powermat -- for the home and places like McDonald's and Starbucks. The device being charged generally must sit on a charging pad that's plugged into an outlet, and often at a very specific spot on that pad. It might as well be tethered.

Pittsburgh-based Powercast wants to give you more room to roam. Here's how its technology works. A transmitter broadcasts radio frequency energy on the 915MHz ISM band to a receiver embedded in a device, and the receiver converts that energy to direct current to power the device or charge the battery.

That's on the receiving end. For the transmission side of the process, Powercast is hoping that consumer goods manufacturers will soon start building the technology into products such as lamps, appliances, set-top boxes, furniture and car dashboards.

Also on Tuesday, another company announced it had received FCC certification for its own over-the-air wireless charging technology. San Jose, California-based Energous said that its WattUp Mid Field transmitter can provide recharging to devices up to three feet away, and to multiple devices at the same time.

Going the distance

Powercast said it expects that up to 30 devices within range of a PowerSpot will be able to charge overnight, depending on the distance, as well as the type and power consumption of the individual device. It breaks things down this way: Power-hungry, heavily used devices like game controllers, smartwatches, earbuds and headphones charge best at a range up to two feet; keyboards and mice up to six feet; TV remotes and smart cards up to 10 feet; and home automation sensors up to 80 feet.

Because phones are such heavy consumers of power, charging them will require extra help for the time being, in the form of a PowerSpot-Qi combination. This slightly larger PowerSpot transmitter would still send energy over the air to peripheral devices, but the phone would have to sit on top of the transmitter. That is, it would still be Qi charging.

"We do know that people are going to want to recharge their phone," said Charlie Greene, chief operating officer and chief technology officer at Powercast. "The primary focus of the PowerSpot today is those peripheral devices, and for the short term we see Qi as the solution to go with for charging the phones."

The WattUp system from Energous also is designed to charged devices at the point of contact.

Powercast expects production units to be ready in the third quarter.  You'll find both companies demonstrating their wireless charging tech at CES 2018.

First published Dec. 27 at 12:22 p.m. PT.
Update, Dec. 28 at 6:09 a.m. PT: Adds information about wireless charging tech from Energous.

The Smartest Stuff: Innovators are thinking up new ways to make you, and the things around you, smarter.

CNET Magazine: Check out a sample of the stories in CNET's newsstand edition.