Macworld clears up confusion around iPhone 'charge cycles'

Wow I hope it really does last longer than the panic is saying it will. I did some looking though and I'm not as worried about it as I was. I found that ipodjuice.com already has a service in place to replace the iPhone battery that is less expensive than apple's. Good to know we will have options.

To be fair, I had quotes from Apple and all Gizmodo did was correct their earlier error. So my story took the story a little further than Gizmodo's correction.

Guys, as much as I like TUAW and some of the other blogs, don't you think it's a little bit unfair to credit Macworld with clearing any confusion whatsoever regarding this when Gizmodo reported this story two days ago and made it to the Digg front page because of they were the first to do so. It's not like they are obscure sites, aren't they?

Anyway, cheers and keep up the good work.

karllaqi, you're scaring me!
I'm hoping someone at Apple sees that-- nice find

The "confirming a widespread bug" link points to the charge cycle information, no? I would like to know what the bug is.

WHAT confusion?

http://www.apple.com/batteries/

Nothing confusing here, it's all there in short, simple words for anyone to read.

RTFM, people!

1. The iPhone uses the same 'new generation' batteries as in the iPods; Lithium Polymer / Lithium Ion.
2. Complete discharging/recharging is *not* necessary, short charge cycles are fine. (Once a month or two and when you first get the thing is probably a good idea however to exercise the battery and to educate the computer as to the battery's expected life.)
3. From my understanding (but I've seen precious little of this mentioned) the 'maximum life' of a lithium polymer battery is actually after a few full cycles. That is that the chemistry itself needs to be used a bit before it will get its deep long cycle lengths.
4. Very very very smart chemistry type geeks have been devoting their lives to making these batteries as worry-free as possible; humor them, don't worry about your battery, fill'er up when she's needing some juice, plug it in if you don't want to drain it... Enjoy the iPhone/iPod, don't worry about the battery.
5. If you want to learn more- google lithium polymer battery, there's plenty to fascinate you if you're into the technology, Apple just bought them to power the phone.

first off, I love, love, love my iPhone. That said, I found my first actual undeniable iPhone bug yesterday. There seem to be a few unresolved issues with the iPhone's calculator. If you have an iPhone, you can follow along at home.
Open the calculator
Press 'C' if there's currently a number in the register
press '4', '+', '5', and '='. As you might expect, you get '9'.
Press the 'home' button on the phone to return to the phone's launch page.
Now say you want to add 3 and 8. Re-open the calculator. After a moment you'll see the '9' return to the register. Nice, and expected.
Press '3'. Instead of clearing the register and showing '3', it appends the 3 to the existing 9 and now you have '93'. This means that every time you launch the calculator you have to clear the current entry before doing a calculation.
This is a strange issue so I had to go to Apple's desktop widget calculator to get a few facts straight. The desktop widget, like a conventional calculator, treats '=' as a terminal action, and will automatically clear the register if the next keypress is a digit. The hiding or showing of the widget has no bearing on the calculator's state. For example, if you're entering your bank account balance into the calculator and forget what the cents were you can exit the dashboard, look it up, re-invoke the dashboard and finish typing the number. On the other hand, if you finish a calculation by hitting '=' and leave the dashboard the number will still be displayed upon your return, but pressing any number will clear the register and start a new calculation. This is the same behavior as if you never left the calculator.

The iPhone's calculator doesn't seem to remember its full state, only the last number in the register. You can exit out of the calculator to lok up a number and come back and finish entering it, but if you've finished a calculation and leave the calculator, it's forgotten that you're not still in the middle of typing a number, forcing you to hit 'C' before you start.

If that were the extent of the problem it would be only mildly strange, but here's where it gets a lot weirder:

Open the calculator
Press 'C' to clear the register
Calculate '5 divided by 8'
Press the 'home' button and return to the launch page
Re-open the calculator
Watch carefully: The display says '0.625' Now press '5'. the display now says '11.25'! Press '4' and it now says '116.5'! What strange witchcraft is this?
It appears that the calculator uses the following logic to enter digits: On keypress 'N', multiply the register by 10 and add N. Following this logic, when the computer has '0.625' in the register and you press '5' it first multiplies 0.625 by 10, yielding 6.25, then adds 5 to it, totaling 11.25. On pressing 4 you get 11.25 * 10 + 4, or 112.5 + 4, or 116.5.

That solves the mystery for adding integers, but how does the calculator add the portion to the right of the decimal point?

Go to the calculator, enter 5 / 8, close and re-open the calculator.
Type '.'. Everything looks good and the display resets itself to '0.'!
Now type '2': You get 0.8.
Type '2' again: 0.84.
Type '2' again: 0.847.
Type '2' again: 0.8472.
Type '2' again: 0.84722.
This is basically the same bug, but it also demonstrates that the display register and the actual register aren't the same. When you typed '.' it automatically set the display to show zero significant digits of the actual register, so while the register still contained '0.625' it was only showing the '0.' portion. Pressing '2' pushed the display register to show one more significant digit (0.6), and added '2' to the least significant visible digit, yielding '0.8'. Pressing '2' again pushed the display to 0.82 and added 2 to the least significant visible digit, making 0.84. Pressing '2' again turned 0.825 to 0.827. Since subsequent digits were all zeroes, subsequent '2' presses behaved normally.

There are other oddities as well, mostly having to do with rounding that happens between the memory register and the display register. For example:

Divide 97 by 100 to yield 0.97.
Quit and re-open.
Press '.': The display now reads '1.', because that's 0.97 rounded to zero significant digits.
But wait, 0.625 rounded to zero significant digits is also 1! It appears that the relevant rounding occurs two significant digits below the current display. '0.94' closed, reopened, and '.'ed gets you '0.', as does '0.948', however '0.95' gets you '1.'

The point is that there are still a few bugs in the calculator, so be sure to hit 'C' before starting a new calculation, because some manifestations of the bug might not be quite so obvious when you're punching in a s

"charing" your iPhone's battery?

I'm curious about what "the life of an iPhone" IS exactly. The 2 year phone contract? That's about as long as mobile phones last, but shouldn't something as expensive as an iPhone last longer?