Opinion: How Apple could have prevented the iPhone-slowdown controversy

Re:Opinion: How Apple could have prevented the iPhone-slowdo... by cesarb on Saturday December 23, 2017 @06:03PM (#15996794)

Due to the length of the wire leading to the AC adapter, it probably can't respond quickly enough to the voltage drop. The battery is much closer. A solution would be to use a big enough capacitor on the phone end of the wire, but phones are very space constrained, and since the battery is non-removable, it can be used as sort of a "capacitor" for these instantaneous power demands, so there's no need for the extra cost and space of beefier input capacitors.

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Re:Opinion: How Apple could have prevented the iPhone-slowdo... by ComputerGuru on Saturday December 23, 2017 @06:49PM (#15997012)

I know what you’re saying and see where you are coming from, but that’s not how it would work in reality. Presuming sufficient voltage at the the cable (ie no extreme loss due to internal cabling resistance) the length of the cable should not matter.

The real limiting factor is that a basic USB plug charger puts out only 2A while the iPhone’s peak draw at the same 5V can be well north of 2.5A if you’re using the GPU to its fullest.

However it’s not just the power cord that’s supplying current when you’re plugged in - if it were designed correctly there’s no reason those 2A couldn’t supplement whatever your battery is already putting out and only charge it with what’s left over. In fact, that’s how iPhones can stay at 90% while plugged in to a car charger, running GPS, playing audio at the loudest, and streaming some data in the background while some android models would discharge even while plugged in... but both would be dead a lot sooner if they weren’t plugged in.

The real problem is just shoddy engineering. Hardware isn’t much different from software: what all this boils down to is the equivalent of someone writing code that went into production across millions of devices around the world that assumed input x would always be greater than y and didn’t bother with any exception handling or bounds checking. And when that voltage/current combination coming in is insufficient.. an unhandled brownout exception occurs.

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Re:Opinion: How Apple could have prevented the iPhone-slowdo... by walterbell on Saturday December 23, 2017 @07:56PM (#15997266)

There’s also the USB-C adapter which can fast-charge iPhone/iPad quickly via Apple-specific charging protocol, which clearly provides much more power than than the battery does.

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Re:Opinion: How Apple could have prevented the iPhone-slowdo... by DonHopkins on Saturday December 23, 2017 @08:26PM (#15997366)

And if USB-C doesn't provide enough amps for you, there's always jumper cables.

https://www.engadget.com/2014/07/14/junojumpr-jumpstart-your...

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Re:Opinion: How Apple could have prevented the iPhone-slowdo... by ComputerGuru on Saturday December 23, 2017 @10:06PM (#15997660)

I have to admit I’m a bit disappointed. I was hoping to see a real, full-size car battery.

I actually have three absorbent glass mat batteries hooked up to a Noco Genius battery tender and a 1000W 12V inverter to provide battery backup for my sump pumps (long story). Losslessly converting that to 5V shouldn’t be too hard.

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Re:Opinion: How Apple could have prevented the iPhone-slowdo... by ComputerGuru on Saturday December 23, 2017 @09:59PM (#15997637)

Oh absolutely. I was only playing devil’s advocate - in practice even 2A is enough juice and my iPhone 6S would pass out at 60% _within a year of buying it_ when I was doing nothing more than reading Hacker News - I can’t imagine that takes up much power at all!

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