iPhone battery meter is a liar!

Discussion in 'iPhone' started by jellybean, Jul 10, 2011.

  1. jellybean macrumors regular

    Jun 27, 2006
    I've never quite understood this and I can't seem to find an exact explanation anywhere. If I charge my iPhone up to 100% and take it off charge shortly after it's reached 100%, the battery will drop much faster than if I were to leave it on charge for a few hours after it's reached 100%.

    For example, if my iPhone's been on charge all night, in the morning when I start using it the battery meter will remain at 100% for a couple of hours before dropping to 99%.

    But if I charge it during the day and take it off charge shortly after it's at 100%, it'll drop to 99% within ten minutes of use.

    So in both instances the battery meter reads 100%, but one will last a heck of a lot longer than the other, even though they both start from 100%. What gives?
  2. RafaelT macrumors 65816


    Jun 9, 2010
    Lakeland, FL
    Have you tried running it down until it powers off and then charging it all the way? It may just need to be calibrated.
  3. brijazz macrumors 6502


    Jul 31, 2008
    This may sound obvious, but your battery will deplete more quickly depending on what you're using the iPhone for, and what features are enabled.

    Five minutes of playing Angry Birds is not equal to five minutes of checking e-mail. Having your Bluetooth enabled will drain the battery more quickly than having it disabled. Screen brightness is also a factor.
  4. mfr1340 macrumors regular

    Mar 4, 2011
    n. cal
    Batt Problems

    Get batt plus, free app. It will tell you how much time you have left for each type of use. Also you let it go to 20% left before you charge and turn on batt pluss. It will fully charge your phone. Do it once a month. It keeps charging for awhile after it says 100% to get a full charge.
  5. quizzi macrumors regular


    Dec 13, 2010
    You may be possibly running apps in the background during the day, when you charge your iPhone. Ensure that once you have fully charged your phone then double-click the home button and delete all the apps that are in the multi-task bar.

    Try this and see if it makes any difference. ;)
  6. forcetactic macrumors 6502

    Jul 30, 2010
    No way of measuring battery accurately so what you see is not surprising. What matters is they will both drain to 0% with same amount of time
  7. Givmeabrek macrumors 68040


    Apr 20, 2009
    Easy solution for you:

    Setting, General, Usage ,Battery Percentage set to Off. Problem solved.

    There is no battery meter that will have the accuracy that you are demanding, because no battery has that kind of accuracy.

    If that is your only problem your phone must be doing just great!! :cool:
  8. trigonometry macrumors 6502


    Jun 19, 2010
    South Carolina
    This is normal. When you leave it plugged in at night it trickle charges. Source: Battery Doctor App.
  9. Apollo 13 macrumors 6502a

    May 29, 2010
    This happened with every smartphone i owned. So its normal to me.
  10. nateo200 macrumors 68030


    Feb 4, 2009
    Northern District NY
    Nothing is perfect. I'm just glad I have a semi-accurate percentage of my battery...:cool::rolleyes:
  11. maclaptop macrumors 65816


    Apr 8, 2011
    Western Hemisphere
  12. Savor Suspended


    Jun 18, 2010
    There is a trickle charge. Getting to 100% means it was a fast charge. You need to give it more time to consider it a full charge. Try not to use the phone when charging. Agree with the earlier poster and turn off the battery %. My phone on occasion can be stuck on a certain % for a longer time and drain faster after that. As long as you are getting close to the same usage. Right now, my usage is lying to me. I check to see 2 hrs and 50 min, put it down for 15 min without using, and then states 3 hrs and 5 min. It creeps up. This is suppose to happen to standby, not usage. Just turn off the %. Measuring things by 1% is not accurate and makes people OCD. And if you had the phone for over a year, batt life on any phone is bound to get worse as time goes by and you keep charging it.
  13. saving107 macrumors 603


    Oct 14, 2007
    San Jose, Ca
    Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_3 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8J2 Safari/6533.18.5)

    I agree with Savor.

    Apple used to list Fast Charge and Full Charge under the tech specs, they claimed 2 hrs was a fast charge (80%, though it would register as 100%) and 4 hrs for a Full charge (100%).

    I don't see it listed anymore but they still list it under the iPod nano tech specs (1.5 hrs fast charge, 3 hrs full charge)
  14. PNutts macrumors 601


    Jul 24, 2008
    Pacific Northwest, US
    I agree with turning it off. 100% charged is 100% charged no matter how you got there, but that doesn't mean the % shown is correct.

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

    Standard Charging

    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.
  15. Interstella5555 macrumors 603


    Jun 30, 2008
    According to everyone, that joke stopped being funny 10 months ago.
  16. mikelegacy macrumors 65816


    Dec 5, 2010
    Pittsburgh, PA
    Your battery is starting to gain a memory. You need to do more full cycle charges. (less than 10% to 100% charge)
  17. err404, Jul 11, 2011
    Last edited: Jul 11, 2011

    err404 macrumors 68020

    Mar 4, 2007
    There are simply too many variables effecting battery life and performance to provide the user with more than a rough estimation(+-5% best case). With this in mind I feel that the percentage view of battery life only serves to clutter the status bar. The battery icon serves as a more realistic indication of how much information the OS really has on battery life.
    Don't get hung up on the percentage shown. Instead focus on the actual battery life.
  18. decafjava macrumors 68030


    Feb 7, 2011
    NOT with lithium batteries, only the older ni-cad ones.



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