calibrating batteries

Discussion in 'MacBook Pro' started by volcom1151, Mar 27, 2009.

  1. volcom1151 macrumors member

    Feb 9, 2009
    I have a 15 UMBP and I have seen forums on calibrating batteries for these computers and I am wondering what it does and how to do it....
  2. fteoath64 macrumors regular


    Nov 16, 2008
    I am just doing it for my AIR. Drain the batteries and until it will NOT boot even with power button.

    Wait 4 hours. Then plug in charger and not use for at least 6 hours (just leave overnight) and you are done.
  3. GFSarah macrumors regular


    Jan 19, 2009
    North Carolina
    The answer to your question can very easily be found by simply searching the forums here or looking it up on Apple's website. No need to create yet another thread on it (and in fact, it goes against the terms & conditions of the forums).

    But to be nice and sum up the answer to your question:

    Drain it completely - from fully charged until it shuts itself off (you don't power it off). After it dies on it's own, let it sit dead for about 2 hours. Then charge it -uninterrupted- back to full capacity (and leave it plugged in for an additional 2 hours or so). It doesn't matter whether you use it during the recharging or not, it will still be calibrated as long as you leave it plugged in for about 2 hours after reaching 100% capacity.
  4. iLog.Genius macrumors 601


    Feb 24, 2009
    Toronto, Ontario
    Sarah basically got it, but before letting it drain completely, you want to fully charge it first and let it sit charged for at least 2 hours and then let it drain and let it sit on empty for at least 5 hours and then charge it back up to full.

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