Apple was right to scrap AirPower.

Why Apple was right to scrap AirPower

Wireless chargers use electromagnetic induction introduced through a wire coil, which must be matched up to a coil in each device. A charging pad draws current from the wall to create an electromagnetic field.

Third-party charging pads for iPhone, Apple Watch and AirPods utilize a coil for each device. Users generally must move their devices around until they find the exact right location to begin charging.

But Apple wanted a charging pad that didn’t require such precise positioning of the device. So it designed a mat with several overlapping coils.

I have been sceptical of the benefits of wireless chargers for a while. I'm not surprised Apple cancelled this product. To me, the tradeoffs (longer charging cycle, inability to use the device while charging) outweigh the sole benefit; not using a cable. I think wireless chargers, in their current iteration, are not a compelling solution to, in my opinion, a triavial problem. I understand the appeal to consumers. They want a device that is powered by magic. All those power cables are a reminder of the real world.

Someday we may all have fusion power generators in our homes, cars, and portable devices. Eventually, someone will invent a way to store 200 terawatts of electricity in a compact stored energy cell. Someday. But that future isn't now.

Wireless charging pads use electromagnetic induction to juice up your phone. Both the pad and your phone contain wire coils: the pad draws current from the wall and runs it through the coil, creating an electromagnetic field. That field induces an electric current in your phone’s wire coil, which it uses to charge the battery.

However, the electricity being transmitted to your phone isn’t perfectly clean or ideal. It generates some noise, which can interfere with other wireless devices. That’s why the FCC (and regulatory bodies in other countries) set strict limits on wireless emissions.

Noise from a single coil might not be a problem, but each charging coil generates a slightly different waveform. When those waves overlap, the constructive interference intensifies their strength. Just like when two ocean
waves collide and combine their height, radio frequencies can combine their intensity as they interact.iFixit

The hype around AirPower charging was ignoring things that I learned in my Power Systems engineering courses at Georgia Tech over thirty years ago. How were they going to handle electromagnetic interference to other electronic devices? In my youth, my family lived in countries with 240V AC. My father used voltage transformers to provide suitable power to the American made electronics in our home; television, Hi-Fi, etc. The transformers were always warm to the touch, even when the devices were powered down. How was Apple going to handle the heat?

Apple had ambitions to solve these problems. Rene Ritchite wrote on iMore:

It wasn't going to be Qi standard either. Because Qi couldn't do that back then. It was going to be beyond what the Qi standard could do, but Apple said they were going to work with Qi to make it part of a future standard so that everyone could benefit from whatever advancements Apple brought to the table.

But, to date, absolutely no one has been able to do what Apple set out to do with AirPower.

Yeah, not even Apple.

Is wireless charging worth it?

Just how fast is “faster wireless charging” in iOS 11.2? (BirchTree)

NOTE: Samsung’s “Fast Charge” charging pad does not have any hard numbers I can find that indicates how much power it will provide. The below findings display a notable change from previous testing of wireless charging I’ve done. I’ll update this article if I can get more information on th...

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I still don't understand the current fascination with wireless charging. It was clear to me that unless wireless charging could meet or exceed the rate of wired charging, that it was more of a gimmick than a feature. It takes longer to charge the device; significantly longer.

Just a short drive, 30-minutes, using mapping software will drain a phone battery significantly. I've driven on long trips from New Jersey to Connecticut, Toronto, and Michigan while using my Apple Maps and listening to music on my iPhone. The iPhone remained plugged in the whole trip and at the end of the trip was fully charged. Is there a dash mounted wireless charger that allows the user to see the phone and mapping display while driving and listening to music and keeping the phone charged?

The user has to carry the wireless charger and plug that in somewhere and put the device directly on the charging pad. What's the advantage over just plugging the device into a faster wireless charger? If the charging port is removed from devices like some people suggest, how will we charge our phones after half a day walking around Manhattan?

Wireless charging will be more useful someday, in the future, but not today.

Matt Birchler writes:

Over the 2-hour test, the iPhone 8 Plus went from zero to 47%. It charged at an incredibly consistent 4% per 10 minutes. Previously I got up to 40% with this same charger after 2 hours, which is a 17% improvement in wireless charging speed. While this is indeed an increase, it’s not the sort of increase that’s going to get you from “wireless charging is too slow” to “I love wireless charging!”. If you have 2 hours to change your phone and there is a 7% difference in the change level, I don’t think that’s a huge deal. Especially when you compare 30 minutes on the charger, I saw literally no change in performance, as it took 30 minutes for the phone to reach 11% charge.

Wired charging remains the fastest way to charge the iPhone in 2017, and it’s not even close. It’s popular to hate on the charger in the box, but the stock iPhone charger gets the iPhone 8 Plus to 79% in 2 hours (68% faster) and up to 21% at the 30-minute mark (91% faster). That’s a pretty striking difference, and if speed is of the essence, it’s a much better way to get topped up fast.

Things get silly when we look at the true fast charging option that Apple has for the new iPhones. The 29W power brick and a USB-C to Lightning cable charge the iPhone 8 Plus to 100% in 2 hours (112% faster) and the difference is even more striking at the 30-minute point where this gets the phone to 43% (391% faster).