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Comment by lallysingh | Hacker News Reader

If I were being generous, I'd say that there are parts of the charging process (variations in charge, temperature, etc) that the hardware can't monitor, but have to be kept in certain ranges to maintain good lifetime/safety for the battery. So, instead of adding the sensors, they're restricting the charging devices. I can imagine that wireless charging is a bit complicated (see apple's problems) and it's easy for other vendors to get it quite wrong.

If that were the case, I think that they should include the stand with the phone.

Otherwise I think it's a bitter-tasting money grab.

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All Qi chargers already have a temperature sensor in them and any modern phone has many temperature sensors (MEMS sensors, SMPS, lipo battery charger). The Qi receiver already communicates back to the transmitter and can tell it to increase or decrease power. Having the Pixel 3 decrease charging rate if it noticed heating up would be trivial.

You're forgetting the problem of the charging stand being implemented incorrectly & catching fire. Phone sensors won't help you there & while you may think all Qi chargers would have a temperature sensor in them, the fact that something simpler like knock-off USB charging blocks cause fire hazards leads me to not be so bullish on the Qi front.

And hey, look.

https://www.youtube.com/watch?v=CEGlmQS692w https://www.youtube.com/watch?v=IxstYrJQkk8

I'm sure you can find more examples. Just because we'd like the world to work a certain way doesn't mean it actually does in practice & the job of engineers sometimes is to deal with the reality of the world.

The issues you raise aren't solved by limiting transmit power - they are only solved by actually using Qi standard chargers. If you are using a faulty transmitter it can catch fire at 5W or 10W.

The Qi standard as of 1.1 has the receiver communicate back to the transmitter the amount of power it has received. The transmitter then calculates transmit efficiency based on the amount of power it is outputting. If the efficiency is too low the transmitter will fault with the assumption that it could be heating up a foreign object.

>Otherwise I think it's a bitter-tasting money grab.

It's engineering laziness. Designing a phone robust against bad chargers is harder than designing a phone to work with one charger and putting DRM on it. It's the kind of thing markets can't do very much to solve which requires regulation, unfortunately, because there are too many bad actors.

i get that this is theoretically inconvenient for you, but how big of a problem is this really? afaik, most people don't wirelessly charge their phones, even if they have capable devices, and the pixel line tends to be pretty low volume to begin with.

given the small number of people that actually care and the possibly large cost of supporting full speed charging on a wider range of chargers, I'm not sure this is a problem at all, let alone one that merits new regulation.

If you assume faulty charger, you have to figure out a way of dropping at least 5 extra watts of heat somewhere in your phone. That seems practically impossible without significantly compromising on mechanical properties of your device.

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