Battery never reaches 100%

Discussion in 'MacBook Pro' started by Dean87, Dec 29, 2007.

  1. Dean87 macrumors newbie

    Dec 27, 2007
    I charged my macbook for the entire night I was at around 67% before I did and although the light was green, the battery reads 99% all the time. Why is that?
  2. aethelbert macrumors 601

    Jun 1, 2007
    Chicago, IL, USA
    I'm not exactly sure why it happens, but it's perfectly normal. Don't worry about it, happens to me all the time and my battery has over 100% capacity after 122 cycles.
  3. phatboy macrumors member

    Sep 20, 2007
    i got my macbook pro today and i tried getting it fully charged and it said it was only 99%.

    in th istat widget it said 100% though. wiiiiiierd, but apparently its normal.
  4. e12a macrumors 68000


    Oct 28, 2006
    There is a difference between Health and Charge.

    Generally when plugged in, the charge will be in the high 90s, if not 100. It slowly goes down to 95 (when the battery reaches 100, the charger begins trickle charging) and then returns back to 100. So it won't stay at 100 despite being left plugged in.
  5. Dean87 thread starter macrumors newbie

    Dec 27, 2007
    Thanks for the reply guys! It's at 100% it just drops down to 99% quickly.
  6. x0r-lord macrumors member

    Aug 31, 2010
    Ottawa, Canada
    I dont think your using the term "Trickle Charge" correctly. its used to explain the process by which the natural discharge of a battery is countered by an equal charge. thereby maintaining a charge of 100% despite naturally loosing voltage (even when not operating). Trickle chargers dont lower voltage, not only that, but they can't detect that their overcharging it. trickle chargers are not long term use.

    a Float Charger has circuitry to detect the decreased output voltage of the battery and charges upon detection, this is more likely the case, it also prevents overcharging. proper float charging should charge my battery from 98% to 100%.

    I can't explain why the battery doesn't say its charged beyond a certain percentage (i have the same problem, and I have 5 charge cycles on my MBP). when i bought my mac it said 98%, it still does. I don't believe this is because of the charging process.I believe its a software/firmware bug (like sticking the 2009 firmware on the new 2010 battery?)

    heres my desktop.. its been on for at least 5 hours

    Link to Picture
  7. GGJstudios macrumors Westmere


    May 16, 2008
    Almost 3 year old thread.

    This should answer most, if not all, of your battery questions: Apple Notebook Battery FAQ
  8. elpmas macrumors 68000


    Sep 9, 2009
    Where the fresh snow don't go.
  9. GGJstudios macrumors Westmere


    May 16, 2008
    lol, always the same questions! :p

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