Why is my battery capacity 33%?

Discussion in 'MacBook Pro' started by Lithium., May 7, 2010.

  1. Lithium. macrumors newbie

    Feb 23, 2010

    I've had my Macbook Pro for just over 2 years and recently bought one of the 2010 models.

    I'm about to sell my old one but when I downloaded CoconutBattery, I saw that my battery holds a lot less charge than it did when it was new:


    Have I been doing something wrong or is it just low because the laptop is 2 years old?

    If it's something I've been doing, I don't want to make the same mistake with my new one.

  2. DesmoPilot macrumors 65816

    Feb 18, 2008
    it's seen a lot of use by the looks of it; did you calibrate it every few months like suggested by Apple?
  3. FSMBP macrumors 68020


    Jan 22, 2009
    My two year old MacBook Pro battery died within 11 months and the replacement is only 1.5 years old its capacity is 30% with under 60 cycles. (I clearly got lemons)

    It is possible for your battery to be that low since you have a lot of cycles.
  4. GGJstudios macrumors Westmere


    May 16, 2008
    About Apple Notebook batteries

    Calibrating is done to keep your battery status reporting as accurate as possible, and should be done the first week you get your Mac or a new battery. If you run on battery frequently, calibrate every 60 days or so. If you run plugged in most of the time or if you infrequently use your notebook, calibrate every 30 days or so.
    If you interrupt the calibration process or feel that you didn't do it properly, it's fine to start over and re-calibrate. You won't hurt anything.
    Calibrating a portable computer battery

    To check battery status, use iStat Pro or coconutBattery or
     > About This Mac > More Info... > Hardware > Power > Charge Information:

    Be aware that battery readings are not 100% accurate, so if your brand new battery health is somewhat less than 100% or if it fluctuates up and down over time (100%, 96%, 99%, etc.), don't worry. This is completely normal. It's also normal for it to stop charging when you reach 97% or 98%, etc.

    You don't have to worry about anything unless your battery health drops to under 80% with fewer than 300 cycles. In this case, assuming your battery is properly calibrated (so the readings are as accurate as possible), you may have a defective battery. If so, contact AppleCare to see if they will replace it.

    Determining Battery Cycle Count
    AppleCare support recommends that if you leave your Mac plugged in most of the time, unplug it every 2 or 3 days and run on battery down to somewhere around 50%, then plug it back in. That keeps the electrons moving.

    Also, it is not recommended to run your Mac on the A/C adaptor with the battery out.

    As long as you're running it on battery at least every few days and calibrate every month or two, you'll be fine. Relax and just enjoy using your Mac!
  5. andrew086 macrumors regular

    Dec 31, 2009
    could have to do something with those 727 cycles.
  6. cluthz macrumors 68040


    Jun 15, 2004
    Those old batteries was made to last 300 cycles, so it's pretty much used up.
    My old mac had about 85% at 500 cycles, then dived to 60% at 600 cycles and I replaced it.

    33% after 700+ cycles is normal.

    Btw, new batteries are made to last 1000 cycles
  7. AreYouIn? macrumors 6502a


    Jun 9, 2009
    Wow I've had my macbook for 3 years have 986 loadcycles and I'm still at 95% health. Mine did read 80% at one time but that was after not calibrating it for about 6 months. I did and I'm back up.
  8. Lithium. thread starter macrumors newbie

    Feb 23, 2010
    Thanks for all the quick replies :)

    I wasn't aware that you have to calibrate the battery - I've added Apple's reminders to my iCal.

    I'll try calibrating this Mac tonight to see if the capacity improves :)
  9. snaky69 macrumors 603

    Mar 14, 2008
    Don't get your hopes up, the battery in it is designed to last 300 cycles, your has already more than twice that.
  10. johnnymg macrumors 65816


    Nov 16, 2008
    10+ :p
  11. cluthz macrumors 68040


    Jun 15, 2004
    Thats amazing, most batteries go bogus after 500

Share This Page