Battery indicator inaccurate?

Discussion in 'MacBook Air' started by qwdudeqw, Dec 30, 2014.

  1. qwdudeqw macrumors newbie

    Dec 30, 2014
    Hey all,

    This is my first time posting on this forum, so please forgive me if this has been discussed before!

    I just got my new Macbook Air 2014 yesterday and absolutely love it, but I'm slightly concerned about the battery estimated time remaining indicator. Sometimes at 90+% it would tell me I have like 4h left...and then i'd keep using it to 50%, it would say I now have 20 hours left, and then now at 36% it's saying 15 hours...These numbers are kind of unbelievable (I'm also using the battery health app which is giving me similar numbers)

    Is this simply because I have a new macbook and the estimator is still trying to get used to my usage? Or could this be an issue with calibration (but I read online to never calibrate the new Macbook Air batteries myself b/c draining it would cause damage...)

    Thanks for your help!
  2. AppleDApp macrumors 68020


    Jun 21, 2011
    In my experience the the time remaining has never been accurate.
  3. kage207 macrumors 6502a

    Jul 23, 2008
    Completely depends on what your doing with your MacBook. If I'm just using Safari I get like 7/8hours of usage on my MBA (note: No video). If I'm doing iOS or web development I get like 4/5 hours of usage. Though my indicator is usually right and adjusts according to the programs and CPU usage.
  4. motrek macrumors 68020

    Sep 14, 2012
    Power usage varies dramatically from moment to moment and the computer has no idea what you're going to be doing in the future.

    At idle your processor will use ~0.5 watts and maxed out it will use 15 watts. That's a 30x swing. It's the difference between 3 hours of battery life and 15.

    The battery life estimator works off of how much power you've been using in the last minute or so and tries its best, but it doesn't have a crystal ball. Huge swings are to be expected.

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