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The other day my younger sister had her iPhone plugged in via Lightning cable to the wall and she then put the plugged in phone on a wireless charging dock.

She swears it makes the phone charge faster and won't listen to me tell her that the engineers probably didn't design it that way.

Is there any formal documentation from Apple where they mention this use case (and whether or not it would actually charge the phone faster?) I suspect anything but a document written by Apple won't be enough to sway her opinion.

  • It can't but even if it could, the iPhone limit these days is probably battery health, not how fast you can pour electrons in. If you were able to trick it into charging faster, you'd probably cut your battery life down significantly--possibly it would only last a couple months. (Total guess) – Bill K Oct 29 '18 at 16:18
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    @BillK her logic was something like "You can charge faster by getting a different power block to plug into the wall, so clearly there's still room for things to go faster. I'm just mimicking having a stronger block by charging from another source too!" – scohe001 Oct 29 '18 at 16:20
  • Ahh, sorry, you are right--I need to read more closely. – Bill K Oct 29 '18 at 16:22
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    "charge faster by getting a different power block" - only up to a point. To over-simplify, you 'push' Volts but you cannot 'push' Amps. Amps are 'pulled' by the device being charged, so if you plug an iPhone into a 0.5A charger.. it's slow because no matter how hard the phone pulls, it is starved. If you plug it into a 2A [eg iPad] charger, it will only pull 1A. – Tetsujin Oct 29 '18 at 16:50
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    @BillK Not really, Li-ion like it fast and hard. What limits lifetime is charging all the way up and discharging down to 0. But phone manufacturers already limited those in software, nothing to worry here. – Agent_L Oct 30 '18 at 12:23
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Your iPhone won't charge wirelessly when connected to USB. If your iPhone is connected to your computer with USB, or if it's connected to a USB power adapter, your iPhone will charge using the USB connection.

Source: How to wirelessly charge your iPhone 8 or later.

  • Is the reason for this that something would break otherwise? Or could it be built differently so that both can work at once? – Fabian Röling Oct 30 '18 at 20:53
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    @FabianRöling That might be a good question on electronics.stackexchange.com – Andreas Oct 30 '18 at 21:08
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    I assume it's the same as the question about two wall sockets: A bit more complicated than just splitting the cable, but easily doable. – Fabian Röling Oct 30 '18 at 21:40
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    @FabianRöling Most likely it's cost-vs-benefit analysis. It would impart some cost to allow the phone to charge from 2 sources at once. The benefit would be marginal, as using 2 chargers negates benefits of both wireless (convenience) and wired (efficiency) systems, so almost nobody would use it. Most people wouldn't even realize it's possible. Bigger wall bricks are already widely available, better in every aspect and understood by consumers, so why put effort into something that nobody would notice? – Agent_L Oct 31 '18 at 15:00

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