iPad mini Charged my battery to 100% unplug it and it goes down to 99%....

Discussion in 'iPad' started by lina231, Dec 24, 2013.

  1. lina231 macrumors regular

    Aug 7, 2013
    So I just unplugged my iPad mini that has been charging all night. It said 100%, but when I took it off the charger it goes down to 99%. Is that weird? Has anyone else had this problem? Could it possibly mean there battery is no good?
  2. JGWolven macrumors regular

    Oct 10, 2013
    Nah. It's normal. My Air does that as well. Once the iPad hits 100% it stops charging. Just check how much usage you have at 1%. That's the real indicator.
  3. Lucille Carter macrumors 65816

    Jul 3, 2013
    Normal as can be.

    Try to relax and enjoy your iPad.:)
  4. lina231 thread starter macrumors regular

    Aug 7, 2013
    Thanks guys! Ive had my ipad off of the charger all day and its still at 94%. So im assuming that its fine. I am, however, looking into getting applecare for my ipad. Worth it?
  5. TB07-NJ macrumors 68020

    Jul 7, 2008
    Actually it doesn't stop charging at 100% it drops down to a very low trickle charge in order to maintain the 100% while it is on the charger.
  6. JGWolven macrumors regular

    Oct 10, 2013
    That's actually incorrect.

    "So, here’s how things work: 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. "

    It's not a sustained charge like you indicated. That would be an unreasonable waste of power. It can even drop to 98% before it realizes it needs to be charged back up.
  7. iapplelove macrumors 601


    Nov 22, 2011
    East Coast USA
    This is correct, and my Mac does the same
  8. mhdena macrumors 6502

    Sep 16, 2009
    I've noticed my air not charging to 100% overnight after doing so for the 3 1/2 weeks, so I unplug and plug it in again it goes to 100

    My ipad1 I traded for this never did that.
  9. s2mikey macrumors 68020


    Sep 23, 2013
    Upstate, NY
    I went with apple care this time on my Air seeing as it's a new device with plenty of new hardware under there. Made sense to me.
  10. TB07-NJ, Dec 24, 2013
    Last edited: Dec 24, 2013

    TB07-NJ macrumors 68020

    Jul 7, 2008
    We're talking a very low few mAH trickle charge. Don't think it's "wasting" any appreciable amount power. It was actually measured a couple iPhones ago and photos were posted here or somewhere of the tests & setup. Been a few years but it was confirmed by a number of people. Same test have been run on other phone devices as well with the same results. IIRC trickle charge was under 5 mills. It's easy enough to measure just put a USB extension between the cable and USB brick (so you don't have to cut your lightening cable) and break out the 5V line and split it and put a meter inline. Just because a device no longer shows charging doesn't mean it is not being trickle charged. You have to actually measure the current draw with a meter after the charge shows complete.

    It came up trying to prove to people that even if you used a 100 amp hour battery to charge a device it only pulls the max current the circuitry is designed to charge with despite the output of the charger (which has nothing to do with THIS discussion). There was some guy who graphed it with some high end battery testing equipment made for just that purpose.


    Most lithium-ion polymer batteries use a fast charge to charge your device to 80% battery capacity, then switch to trickle charging. That’s about two hours of charge time to power an iPod to 80% capacity, then another two hours to fully charge it, if you are not using the iPod while charging.

    Added (not by Apple) after the previously mentioned testing (the trickle continues at a low rate).
  11. JGWolven macrumors regular

    Oct 10, 2013

    OP is referring to when the device is fully charged. What happens at the end of the cycle (and what OP's post was in regards to) is explained by http://www.macrumors.com/2012/03/27...-continued-charging-beyond-100-battery-level/.
  12. AntnyMikal macrumors regular


    Jun 2, 2012
    If I charge my Air to 100% overnight and unplug it, it will stay at 100 for about 10-20 minutes depending on what I do. My phones, iPods, iPads and MBPs will do the same.

    So it's seems a a little strange to me.
  13. TB07-NJ macrumors 68020

    Jul 7, 2008
    I understand exactly the OP's post was referring to however we'll just have to agree to disagree since I have seen a fully charged iPhone (and other devices) continuously trickle charge for many hours after it is "full" and not "stop and start."


    As does mine. Never comes off the charger at less than 100% and stays there a while.
  14. lina231 thread starter macrumors regular

    Aug 7, 2013
    Hi all,

    Thanks for your replies! I cave in and just called apple, the representative said that it was normal for the ipad to do that. He also said that they never charge to an actual 100%. More like they charge to 99.999999%. If thats true, I have no clue. Either way, I haven't charged my ipad since yesterday and it s at 83%. I was also asking about the applecare for the ipad, and he said that there is no student discount for the applecare for the ipad, which is kind of dumb but whatever. I'm still debating on whether I want to purchase the apple care for it or not.....:confused:
  15. ougum macrumors regular

    Apr 30, 2008
    I bought Applecare for my last 3 ipads. Never used it so it was a waste of money for me. Must admit it did give me peace of mind though. No Applecare for my Air.
  16. samiznaetekto macrumors 65816

    Dec 26, 2009
    99% could be caused by incorrect battery calibration that slowly drifts with time. Remember, the percentages you see is a result of calculation from measurable quantities such as voltage and current. It's not like looking at the marks on a measuring cup. So, if coefficients are off, the % will be off, too.

    If you never discharge your iPad to 0, it never knows where real zero is. As a result, % is off from the true value. Take care of your battery following simple procedures:

    - do a full cycle (charge to 100, discharge to automatic shutdown) once a month
    - if you're not using it for several hours or more, turn it off
    - do not leave it plugged in at 100% for extended periods of time: again, not using it, unplug and turn off
    - if using it for several hours within comfortable reach of an outlet, don't be lazy, use it plugged in - conserve the cycles

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