battery at 99%

Discussion in 'MacBook Pro' started by dinesh89, Jan 29, 2009.

  1. dinesh89 macrumors member


    Dec 30, 2008
    Melbourne, Australia
    Hey guys..i just got my mbp 2.53 yesterday and its really awesome.really happy cos everything is fine..but the prob is it keeps saying its charged but it shows its 99%. i checked istat and it still says its charged but its 99%. even the magsafe light is green. any idea?
  2. Gleadr macrumors member


    Jan 26, 2009
    it is normal it should eventually go up to 100% don't worry and dont call apple because they will say that they wont replace it.
  3. GGJstudios macrumors Westmere


    May 16, 2008
    It's normal. It will fluctuate from time to time, up and down.
  4. 99MustangGTman macrumors 6502

    Dec 3, 2008
    Germantown MD/ Columbus OH
    Sometimes mine does the same thing. It may be just be late to update. Also you may want to properly calibrate the battery too.
  5. angemon89 macrumors 68000


    Feb 5, 2008
    The place where Apple designs stuff
    Calibrating the battery will fix this, but then it'll start showing 99% a few days later again. Just don't worry about it, it's normal.
  6. FarSeide macrumors 6502a


    Feb 17, 2008
    Earth Lane
    good question.. i was thinking the same thing with my new MBP.

    thanks for the info guys
  7. michael.lauden macrumors 68020


    Dec 25, 2008
    at work i work on 99% DC electronics. up to 7.0hp electric motors, 500 amp controllers, solenoids, on board computers. the works

    and i know that the OBC (on board computer) regulates charging

    if you think of it in a different light... while it is very annoying to not have 100% and the green light on the magsafe power adapter is on (meaning it's not charging).. your computer is doing what's best for the battery

    for the most part, over voltage is bad. especially on something as important, and used as a computer battery.

    if your battery was at, per say, 99.4% - there wouldn't be a healthy way for the battery to charge .6%. it would have to be on a trickle charge, and it doesn't make sense to do that for the computer battery, if it's .6% under charged.

    it is healthier to leave it at 99.4% of total charge, than to risk over charging it. also if it DID try to go from 99 to 100% with that small of an increment - putting voltage to the battery to charge for split seconds (pulses) wouldn't be good for it.

    what i usually do (to make sure it's ready for a full day of work, or a day where i know i'll be stuck at the airport) is leave it unplugged for a few minutes and it will go down to 95 or lower, and then the charging will kick back in (actually charging kicks back in even at 99%)

    and it will usually goto 100%.

    trust your machine, it's tryin' to make your battery last you more than a year!

    p.s these are just assumptions about macs, im just basing it off of prior knowledge in another industry!
  8. Acorn macrumors 68020


    Jan 2, 2009
    my blackbook used to show 96% when the battery was full. I did the whole battery calibration thing and now its been at 100% for 2 weeks. so I guess its fixed.

    I read you should calibrate it even when its first purchased. not only for accuracy but it makes your battery last longer
  9. mobilehaathi macrumors G3


    Aug 19, 2008
    The Anthropocene
    You should totally freak out and call Apple immediately. :D:D:D:p:cool:

  10. dinesh89 thread starter macrumors member


    Dec 30, 2008
    Melbourne, Australia
    i see. ok.well i was hoping it wanst anything bad cos i really do not want to return it since there is no problems..thanks alot guys.well just another small question. in istat pro under health it says its 95 % yesterday i had it at 99% together with the charge.
    thanks everyone
  11. 5280m macrumors member

    Jan 16, 2009
    The battery in your macbook doesnt charge until the total charge drops below 95%. Try it for yourself. If you unplug and then let it drop to 94%, then plug it in it will charge to 100% again. But if you run a heave process your computer will pull some charge from the battery to aid it. So I would say dont worry about it.
  12. jargonblimp macrumors newbie

    Sep 30, 2008
    I'll back up what the last post said and confirm that the battery won't charge up until you go below 96%. So if you have 96%, the battery will show full and won't charge up.

    If that disturbs you, have the icon display something other than a percentage.
  13. dwd3885 macrumors 68020

    Dec 10, 2004
    yea the only time apple will replace batteries is if there's a recall, or if for some reason the magsafe connector isn't working at all, they might replace the battery first, before digging deeper.

    my late 2008 mbp does this too-go to 99% and back- it's normal. just let the battery run sometimes and you'll be fine
  14. fartheststar macrumors 6502a


    Dec 29, 2003
    on a related note - just to confirm - if my laptop is not going anywhere for a while, it's acceptable to keep it plugged in all the time?

    I posted here because it said 100%, now 99%, still plugged in <--- not worried about that part (the 1% change), but just wanted to see how you all use your laptops.

    I figured it'd save battery life for when I actually need it.
  15. dwd3885 macrumors 68020

    Dec 10, 2004
    if by while, you mean a week or more, i'd take the battery out and just use it plugged in. otherwise it's probably fine
  16. ValkyrieLenneth macrumors regular


    Jun 28, 2008

    Don't take the battery out because performance will be decreased.
  17. darngooddesign macrumors G3

    Jul 4, 2007
    Atlanta, GA
    If your battery is at 96% (or higher) when you plug it in it won't charge to 100%. Apple does this to stop them from taxing the battery when it drops from 100% > 99% by just moving from one room to another. If you are OCD and its bugging you just run it down to 95% and then plug it in.

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