Batterygate? Apple's iPad "Fibbing" battery charger

Batterygate? Apple's iPad "Fibbing" battery charger

Summary: An expert finds that when your new iPad tells you that it's fully-charged, it's not even close to being charged up. Are we looking at an Apple iPad "Batterygate?"


The new iPad looks great, but it's battery recharging time is something else again.

The new iPad looks great, but it's battery recharging time is something else again.

Dr. Raymond Soneira, president of DisplayMate, the world's leading display and display tuning company, is best known for his graphics expertise, but he also knows his way around electrical engineering and physics. During his extensive testing of the iPad 3's display Soneira also found "that the batteries do not actually reach full charge when 100% is shown and need up to an extra hour before the charging actually stops. So what's up with that?

Soneira found the problem during his iPad 3 benchmarking. He measured "the power actually drawn by the AC Adapter and first found that the new iPad continues to charge for up to 1 hour after it claims to reach 100%. This affects the battery run time if you stop charging when it says 100%." This isn't just an iPad 3 problem. Soneira notes that "Other tablets and smartphones also lie about their charging status."

Further testing by Soneira has shown that "At 2:00 hours after reporting 100% charge the new iPad hardware started to reduce the charging power. At 2:10 the recharging cycle fully terminated with a sharp decrease in power." Thus, "The new iPad battery is truly fully recharged 2 hours and 10 minutes after prematurely reporting on screen that it was fully charged."

What's caused this? Soneira speculates, "The charge indicator on all mobile devices is based on a mathematical model of the charge rates, discharge rates, and recent discharge history of the battery. It uses this information to estimate how much running time is left. It's actually rather difficult to do because most batteries degrade slowly as they discharge and then tend to surprise with a precipitous decline near the end." I think we've all seen that!

But why is the iPad 3 so badly off in its estimate? Soneira thinks, "There is something wrong with the battery charge mathematical model on the iPad. It should not say 100% until it stops recharging and goes from the full recharging rate of about 10 watts to a trickle charging rate of about 1 watt. Otherwise the user will not get the maximum running time that the iPad is capable of delivering."

That full battery charge, according to Soneira's benchmarks, is impressive. At the middle brightness setting the iPad 3 can run as long as 11.5-hours. Since the new iPad has "4 times as many pixels in the display that need to be kept powered [over the iPad 2 and} 4 times as much memory and processing power is needed for the images. In addition, the light transmission of the LCD decreases as the pixel density increases, so a brighter Backlight is necessary. In fact, the number of Backlight LEDs has roughly doubled (from 36 to an estimated 72 to 82), so the Backlight power has approximately doubled. Since the display normally consumes about 50-60 percent of the total Tablet power, the new iPad needs at least a 50 percent larger battery. In fact, the battery increased from 25 to 42.5 watt hours, a 70 percent increase."

The iPad 3 s battery life is remarkablly good.

The iPad 3's battery life is remarkably good.

Somehow, Apple has managed to significantly increase the iPad 2's power density of its Lithium-Ion batteries. In that the key may lie as to why its battery charger is giving incorrect information. Its battery charge mathematical model, and/or the algorithms used to come up with the recharge numbers may simply not have caught up with the iPad's new battery technology.

Or, Apple may have just been "fibbing" about the recharge time. When it comes to battery-issues, most companies share the truth about how long a battery will actually be useful and how long it takes to recharge them. And, last but never least, how people use their battery-powered devices vary wildly and largely determines what really happens with their useful life.

iPad battery life chart courtesy of DisplayMate.

Related Stories:

Apple's new iPad display is better than most HDTVs

New iPad's most revolutionary feature is its battery

CNET: 10 ways to improve iPad battery life

New iPad owners get ready to feel the LTE data cap

iPad 3 'Heatgate' drama is completely overblown

Topics: Hardware, Apple, iPad, Mobility

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  • I'm confused

    This was a well presented, thought through, fairly technically useful blog piece. Is this really zdnet? I wonder what other mysteries might unfold!
    • I'm confused too.

      About why this is called battery gate when what I read basically said the "new iPad" (it's not iPad 3) had remarkable battery statistics. I think maybe the iOS software may need some updating to reflect the true beauty of the new iPad's battery powering and not rely on the version that is based on the iPad 2.

      The more I read, the more I want to make the new iPad my first iPad purchase, rather than waiting another year for the next release of this awesome tablet computer!
      The Danger is Microsoft
      • also...

        its not "new iPad" either... its just the new "iPad"
      • Brilliant reply doh123!

        The Danger is Microsoft
    • Confused too

      but for an entirely different reason.

      The blog stated: "Somehow, Apple has managed to significantly increase the iPad 2s power density of its Lithium-Ion batteries."

      Teardowns conclude a 70% larger battery with 70% more energy. That is precisely the same density. It is amazing what bloggers make up when they write.
    • I too was confused

      Not only by the fact that it is a well thought out, well written, and unbiased article but that the author of this piece was none other than SJVN.
      • I too was confused

        what does that have to do with anything?
  • Sorry

    "Batterygate" has been used. Maybe "Chargergate"? I think that one is still open.
    • Also, some other overboard wording is used:

      "the world???s leading display and display tuning company" -- this guy definitely a professional, but his company is very little organization with only few people around. Not quite "world leading".
      • What does the size of an organization have to do with

        being 'world leading'? If you look at the credentials of that company, I think you will find they set a pretty high standard. Certainly more 'world leading' than you or I are.
      • What "you and I" have to do with anything?

        @whatagenda: I am saying that this is tiny organization, and there are alot of such organizations (including bigger ones) around the world. There is just no way to suggest that they are "world leading" in any thing.
  • Can we ditch the -gate names?

    Seriously, they're getting old.

    But yeah, nice article sjvn. That's not something I can say often, so congratulations.

    I've noticed a similar phenomena on my Android phone. Half the time I go from full battery to half pretty quickly while other times it discharges much more slowly. Thanks for the heads up, I'll start keeping an eye on my charging times.
    • The only time it gets a -gate name

      Is when it is an Apple product, and someone needs a click-bait article. Other tablets, and phones, have this issue. Yet Apple is the only one singled out, again. Remember "antenna-gate"? The iPhone was not the only one to have signal issues, but ZDNet flies out to call out Apple, and ignored Samsung's WP 7 phones (among others) that had similar issues. There were even videos on You Tube, showing it happening to other phones. Yet ZDNet implied it was only happening to the iPhone 4. What ZDNet failed to say was it was only happening to around 3% of the phones.
      Jumpin Jack Flash
  • How about StupidGate?

    I love all these reports of things wrong with Apple products...and I have yet to experience any of them. Had the new iPad for three days without charging it, got close to 9 1/2 hours use out of yet another stupid article on ZDNet based on baseless facts.
    • I'm shocked!

      That comment sounds like something Rick_K would say, not you!
      William Farrel
    • If You Haven't Charged, How Can You Criticize?

      If you haven't charged it, then you haven't had the chance to experience the issue yet. The point of the article is that when you do charge it, it will say fully charged before it actually is fully charged. If you leave it to charge overnight, you probably would never notice this issue either, since by the time you take it off, it will be fully charged. It's not a really big deal; it's just a minor inconvenience (as long as you know about it anyway).
  • I agree, there may be

    something wrong with the battery charge mathematical model for the iPad 3. Its showing the unit 100% 2 hours before it actually is.

    The question is, is it a 'mistake' like the 5 bars of signal strength issue a while ago, or is it deliberate, a way of saying that it charges faster then it actually does?

    Seeing that many people just plug their mobile devices in overnight to recharge, how many would ever really find out if it is off by 2 hours?
    William Farrel
    • How did you determine...

      that an extra 2 hours of charging was required?
  • It is funny you should mention this because...

    2 things I noticed...

    First, I used the new iPad for an hour and the battery finally ticked from 100% to 99% and I was like wow, that is a great battery! Of course it probably is still a very good battery but not as good as it appeared.

    Second, the WiFi signal strength icon shows 0 bars but I have a very good connection from my router and I will be in the same room as the router.
    • So there are two glitches: one is positive and the other one is negative

      ... for user's opinion on device.

      Both should be fixed in the upcoming weeks.