Apple's AirPower Wireless Charger Is Facing Overheating Issues, Says Reports (cnbc.com)

Two separate reports are saying Apple's yet-to-be-released AirPower charger is facing overheating issues. The product, designed to simultaneously charge an iPhone, Apple Watch, and AirPods, was announced more than a year ago at Apple's 2017 iPhone event. Apple has yet to provide any additional information on AirPower, even during its iPhone event last week. The company even appears to have wiped all mention of it from its website. CNBC reports: Tech writer Sonny Dickson, who has a track record of accurately reporting on Apple, said over the weekend that Apple has struggled with heat management, which affects accuracy and charging speed. Dickson thinks it's unlikely Apple will make its end-of-year release deadline. Daring Fireball's John Gruber said something similar. Gruber said the charging pad, which uses a multi-coil design, is "getting too hot -- way too hot."

"There are engineers who looked at AirPower's design and said it could never work, thermally. ... I think they've either had to go completely back to the drawing board and start over with an entirely different design, or they've decided to give up and they just don't want to say so," Gruber said. Apple gave a broad timeline for AirPower's launch, saying it would go on sale in 2018. So it is still possible it can work out any issues before the end of the year.

Comments

Known Problem

[necro81]

I won't be so bold as to crow "Oh, they should have seen this coming." Still, this should not be a surprise, as anyone who has used wireless charging has experienced.

I worked on a product some years ago that was using a competitor to the Qi standard. Our product had a receiver coil that captured the alternating magnetic field, rectified it, and delivered that bulk power to the Li-Ion charge circuit. Worked great, except when you realize that the entire device is immersed in this alternating magnetic field. Every conductor, and in particular every ferromagnetic component (screws, the metal housing of the Li-Ion cell, a metallic portion of the housing, everything) was heating up due to eddy currents. As a stopgap we ended up sticking a ferrite shield over the mat, to isolate only that area where we wanted the charge power to emit. That worked to limit the heating, mostly. But that made it not all that different from most wireless charging cradles before and since, where you have to align the product to the charger. Needing that alignment drastically reduced the utility of the wireless charging, which was one reason why we scrapped it.

Oh, and while we were delivering about 2 W of charge power to the Li-Ion battery, the mat was drawing about 18 W from the wall. Even when the device wasn't present and not charging, the mat drew 10 W. This experience has made me highly skeptical of the prospect of widespread wireless charging anytime soon.

Re:Known Problem

[TheDarkMaster]

Exactly that. Among other things I am a professional electrician, and I wonder how can be safe to have something like a radio frequency emitter strong enough to induce usable current in a coil (which is the operating principle of a transformer) leaning against a delicate electronic device (the cell phone). It's such a risky operation where so much can go wrong that I'm impressed how they might want this rather than a simple cable connecting the cell to a conventional charger.