Apple: iPad 3 battery gauge works as expected

Apple: iPad 3 battery gauge works as expected

Summary: Apple didn't want to show the iPad battery constantly fluctuating between 90 and 100 percent as the battery goes through its normal trickle charge/discharge cycle to keep it topped off.


Apple: iPad 3 battery gauge works as expected - Jason O'Grady

AllThingsD's Ina Fried published an article today indicating that the observations of unusual charing behavior with the iPad 3 aren't so unusual after all.

Yesterday I noted that if you unplug your iPad 3 as soon as the battery indicator says "100%" you’re actually missing out on as much as 1.2 hours (10 percent) of additional run time. But Apple says that this is the expected behavior and that the iPad battery is designed to work this way.

Fried explains it this way:

Apple does, in fact, display the iPad (and iPhone and iPod Touch) as 100 percent charged just before a device reaches a completely charged state. At that point, it will continue charging to 100 percent, then discharge a bit and charge back up to 100 percent, repeating that process until the device is unplugged.

Soneira, President of DisplayMate Technologies Corporation, first discovered that the iPad 3 experienced a net loss of 1.2 hours (around 10 percent) of battery run time if unplugged as soon as its battery indicator displayed 100%. His essential point was that if the iPad 3 is fully charged (i.e. overnight) it will run 11.6 hours, which is 1.2 hours longer than if it is only charged to 100% (10.4 hours).

Apple VP Michael Tchao tells AllThingsD that Apple decided not to keep changing the battery status "so as not to distract or confuse users," explaining:

That circuitry is designed so you can keep your device plugged in as long as you would like, It’s a great feature that’s always been in iOS.

So there you have it. The iPad battery displays "100%" a little prematurely because Apple didn't think that it would be wise to show the battery constantly fluctuating between 90 and 100 percent as the battery goes through its normal trickle charge/discharge cycle to keep it topped off. Makes sense to me.

Topics: Hardware, Apple, iPad, Mobility

Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.


Log in or register to join the discussion
  • How many articles are going to be written about this very

    "smallish" issue!?! Is Apple so good at what it does that ever none events that might point to a very slight problem become (what is it now) 6 articles worth on ZDNet? If so I guess that's kind of good news:)

    Pagan jim
    James Quinn
    • apple is hiding major defects

      It has been proven that apple creates inferior products for higher prices and then brags about features it is clearly outperformed on:
      The Linux Geek
      • And the Apple Haters Speak Again

        Nuff said!
      • Baffle them with BS would be my take

        I agree, they screw up and rather than admit it, they cover it up by saying it's working as we designed it..............pardon me while I call "Bull Sh_t".......
      • Oh come on Linux Geek

        All that article did was rehash half of Jason's first article on the battery issue... but if you want to accept that as fact and be wrong yet again go for it.

        Don't you get tired of being wrong all the time and displaying that fact every single time you make a post here?
      • You have a weak grasp on what the concept of "proven" means

        "It has been proven..."-The Linux Geek

        "Proven" does not mean what you think it means. For one thing, it involves "proof" not just unfounded supposition.
      • Oh, so this is why

        I have a 13-year-old G3 still in use (a friend has it) and we have a 9500 that's 16 years old and still works. Thanks for enlightening me.
        Laraine Anne Barker
  • Much ado about nothing

    The iPad's battery works the same as every iOS battery ever has. The iPad is no warmer than other comparable tablets and cooler than most notebooks. LTE eats up data on your iPad...exactly the same as it does with every other LTE device.

    Talk about much ado about nothing.
  • Annnnnnnnnd....

    You're STILL talking about the battery. I wish one of the technology giants would release a phone or something so you'd quit your incessant babbling about the stupid iPad 3 battery issue. Which, as many of your posters on the previous stories noted, was a non-issue from the beginning based on standard battery behaviors...

    Put down the stick and walk away from the horse Jason...
  • Well, it could be a problem

    when you consider the heat and battery tests run on all the other tablets. Could someone point me to the articles about the array of Android tablets so we can see what happens to those tablets after they show 100%?

    I can't seem to find them.
    • Exactly!

      I want to see the data on Android based tablets as well as the original and second generation iPads.
    • Not sure there is one

      So why don't you go do the testing and let us know.
  • Keep spreading the FUD ZDNet

    Haven't seen this issue yet. My iPad works fine.
  • Very typical

    Once again Apple has swapped utility for the sake of simplifying. Who wouldn't prefer that the device reported a 90% charge and that it has now entered tickle charge mode rather than it reporting it is fully charged? No no that wold make things much too complicated.
    • Absolutely.

      Look at those results. Apple said up to 10hrs and 90% gets you 10.4. I mean, what bandits! They should have, instead, said up to 11 hr and show the charge and discharge cycles because when people see the battery display constant fluctuate between 90% to 100% *surely* we wouldn't see stories about THAT anywhere. "Apple iPad constants charges, increase home power usage .000003%. People outraged!"
    • Who? Almost everybody?

      Being that this is industry-standard charging behaviour, WTF are you babbling about?
  • Most other devices I've seen

    have an animated icon that either replaces the charge indicator, or cycles the bars on the existing one.

    That way you can tell if it is charging, or if the power connector is not plugged in correctly, or if the PSU is actually plugged into the wall.

    Modern devices that use Lithium cells do indeed all have this feature, as it is extremely bad for this type of cell to be overcharged or completely discharged. Overcharging a Radio Control Lithium pack is extremely dangerous as those things can deliver double figures in Watts, and an internal short can get hot enough to cause a fire. Discharging them completely can cause these shorts as crystals grow in the Polymer layer and are repeatedly dissolved by the charging action, weakening the insulation - so the most efficient use of the cell happens above 20%, which is when the device says its empty, even though it is not.

    iPad batteries dont hold enough charge to do serious damage, however their life is also shortened by that kind of abuse, hence the battery management system.
    Most people are now familiar with the fact that modern batteries need to be treated with a little consideration, and watch their charge cycles accordingly. Its just curious to me that Apple have decided to try and hide this standard behaviour because it might 'confuse' users.

    This smacks of treating customers as if they were stupid...
    • Not stupid, just realistic

      As a professional technology consultant that has worked with all sorts of clients, it will amaze you what will confuse people. I still run into people that are confused by two button mice! (which is why Apple still sets the default to single button operation on Macs, but I digress)

      From a usability standpoint, Apple did exactly the right thing. Why add a battery charge indicator that may not be immediately obvious what it means? Especially when most users could care less? If the charge indicator shows 100% and you get the specified battery life, why worry about the technical details of battery management? It's nothing users can control or even need to worry about. It's these fine little details that make Apple products the most usable in the world. An engineer might have thought that a different battery indicator would be a great idea, but most people aren't engineers. Just imagine from a technical support standpoint the number of calls that would have been generated by this subtle little change. "My battery charge indicator is freaking out!" This is just another example of Old World vs New World of Technology thinking and why Apple is the company it is today.
      • If it were designed well, it wouldnt generate tech support calls

        Thats the whole point of good design, its clear and simple. Hiding the process has only generated a whole lot more trouble than fixing the problem would have in any case. Its just curious, Apple pride themselves on design, and thats not the best design I've ever seen.

        And I still think Apple using the excuse that the users wouldnt understand is a bit insulting, given the capabilities of the device and who it is aimed at...
      • And...

        It didn't generate any tech support calls, so what is your point?