New 17 inch MBP Battery

Discussion in 'MacBook Pro' started by Macbobit, May 29, 2009.

  1. Macbobit macrumors newbie

    May 24, 2009
    Hi, I'm happy to say that recently I purchased a 17'' MBP. It's my first mac in years, things have changed a lot but I'm glad to back so as to speak.

    I'm having trouble with my battery however, maybe...

    I've had the computer about 2weeks and have charged it everyday almost, but haven't run it down past 50% on any one time I don't think.

    The battery status information in will only indicate the percentage power left, and leaves 'calculating...' when I select time. For the past couple of days when I checked, the time indicated was 5hrs even though the percentage was at 90%.

    I got the 17'' MBP partly because of it's advertised battery life of 8hrs.

    What's going on?

    Any help would be appreciated.
  2. Zagreus macrumors member


    Jan 9, 2009
    Bradford, West Yorkshire, U.K
    Well Apple's advertised "8 hour" battery life is probably under optimum conditions, i.e low screen brightness, no bluetooth, no airport etc. If you want to turn these features up then that's going to affect the overall battery life. If you want it to run for longer then turn off some of these features if you aren't using them and it should increase battery life.
  3. Macbobit thread starter macrumors newbie

    May 24, 2009
    Any idea why it seems stuck on 'calculating...'?
  4. gr8tfly macrumors 603


    Oct 29, 2006
    ~119W 34N
    Try the calibration procedure: Apple Portables- Calibrating your computer's battery for best performance

    I've only run a "test" once on mine, and got over 6.5 hrs. My web usage was much higher (virtually zero "word processing"), I had brightness set about 15% higher, and had synced my iPhone 5 times. I think it's close enough to say it's as advertised, without having Apple's exact test plan.

    Overall, I'm very impressed with the battery life. I don't run off battery that often, but the few times I have it's been well within real world expectations based on Apple's "8 hrs".

    Oh, and it's VERY nice not lugging around a 2nd battery - both the bulk and the extra weight.
  5. Dale Cooper macrumors regular

    Dale Cooper

    Sep 20, 2005
    It might be because you've never had your battery below 50%. You probably need to calibrate it. Use it til there is no power left and it goes to sleep, leave it like this for 5 hours, then charge it fully. Think this should be done once a month.

    Edit: too slow
  6. Macbobit thread starter macrumors newbie

    May 24, 2009
    Thanks guys I'll try calibrating the battery. I read on the support site (thanks for the link gr8tfly) that you should recalibrate when you first get the computer.

    Thanks everyone

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