How accurate is the Iphone battery percent?

Discussion in 'iPhone' started by wxman2003, Apr 20, 2011.

  1. wxman2003 Suspended

    Apr 12, 2011
    Just noticed that the battery percent display is not always that accurate. I just downlaoded an app and battery showed 90%. I always reboot after download (old habit from android) and after reboot, battery was back up to 95%. Not that I'm complaining as is it was just the opposite with the other smartphones I owned. Just the reboot use to drain the battery a couple percent on those phones.
  2. MaxBurn macrumors 65816


    Nov 25, 2010
    I find the battery indicator pretty pessimistic on my 3gs. When i get the phone down to say 20% it will hover around that range for quite some time. Never actually made it to low batt shutdown.

    Doing full cycles of discharge / recharge is supposed to make it more accurate so old posts say.
  3. Jumpman2033 macrumors regular

    Jun 27, 2010
    Pretty accurate when it hits 0%. I have yet to hit 0% without the phone shutting down.:D
  4. elan123 macrumors 6502

    Jan 26, 2011
    thats seems to be its most accurate time, unfortunately
  5. vincenz macrumors 601


    Oct 20, 2008
    I haven't had any problems with the battery accuracy at all.
  6. chrisbetty macrumors 6502

    Feb 22, 2011
    I use the SBsettings numeric battery percent and it seems pretty accurate
  7. xAnthony macrumors 65816


    Mar 2, 2010
  8. Carlanga macrumors 604


    Nov 5, 2009
    yes you have more battery after reboot because you have less things working on the background and on a frozen state. ;)
  9. Stealthipad, Apr 20, 2011
    Last edited: Apr 20, 2011

    Stealthipad macrumors 68040


    Apr 30, 2010
    ReBooting puts power BACK into the battery?
  10. MaxBurn macrumors 65816


    Nov 25, 2010
  11. Carlanga macrumors 604


    Nov 5, 2009
    of course not :p

    I believe the formula computes battery lifetime based solely on the power consumed. In actual application, the power consumed by the device is often dwarfed by the programs or things connected to it, thus any design must account total power consumed by all components in sleep and active states. The duty cycles from the now not running applications when rebooted will give the battery estimator a different %. :)

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