Battery Health down to 94% after only a few weeks?

Discussion in 'MacBook Pro' started by RoboCop001, Dec 31, 2006.

  1. RoboCop001 macrumors 65816

    Oct 4, 2005
    Toronto, Canada
    Hello. I've just recently purchased a MacBook Pro (2.33GHz C2D), and I'm just a little concerned about the battery health.

    I've looked around for any information about this kind of thing, and I've found some, but I just need to make sure.

    Coconut Battery says my MacBook Pro is 8 weeks old, though I got it about 3 weeks ago. I'm guessing that just means it was actually built 8 weeks ago.

    I did the battery calibration cycle (twice, but not in the past week), but I haven't seen much change in battery health. The first time I did the battery calibration was when I first took it out of the box, but when I got to the draining-the-battery part, I put it to sleep a couple times. So I'm guessing that negates the whole calibration cycle.

    I did a complete "real" cycle a few days later.

    Anyway, Coconut Battery says my battery health is down to 94%. I used iStat Pro too, and at first it was at 99%. Then as the days went on, it gradually went down to 94. Actually, it seemed to fluctuate a bit between 95 and 97. But now it's at 94.

    The number of load cycles is 36. Although I don't remember plugging it in 36 times... but if each drain and charge counts as 2 separate cycles, then I suppose I may have plugged it in 18 times already. I wonder if sleep somehow counts as a cycle... but why would it...

    I use battery power every day. Is it just because of that? I don't let it drain all the way though. I usually plug it back in when it's down to around 20% (that's an average, sometimes it's more, sometimes less).

    I don't do too many CPU-intensive things. When I do, I usually plug it in. And sometimes I just plug it in anyway, just so as not to use the battery.

    However, I remember reading a post in this forum that the person's battery life went down below 90, but then some time later it went back up to 98. I don't remember the exact numbers, but it was something like that.

    Any ideas anyone? Am I using the battery too much? Maybe it'll go back up, but I have no way of knowing.

    Perhaps I should do another calibration cycle to see if it helps.
  2. punkmac macrumors regular

    Jan 27, 2004
    I have a Macbook I purchased a few months ago. I usually have it pluged in and on all the time. When I do unplug it I usually let the battery go way down.
    Why waste the charge right?

    Occasionally I see the battery at 99% then it goes back to 100%. Has yours ever gone back up?
  3. lu0s3r322 macrumors 6502a

    Nov 28, 2005
    don't worry, i think they fluctuate a lot. Just two days ago mine was at 91% and I've only had it for 7 weeks. And right now it's at 100%
  4. tylerboyo macrumors member

    Dec 28, 2006
    Cardiff, UK
    Few weeks ago, mine was down to 94 or 95, and now its 98. I wouldnt worry.
  5. aaron.lee2006 macrumors 65816


    Feb 23, 2006
    Ontario, Canada
  6. Mitthrawnuruodo Moderator emeritus


    Mar 10, 2004
    Bergen, Norway
    Just, use the battery a bit (which coincidentally also is Apple's advice on batteries) and drain t completely every now and then (and not just down to 20%).

    My 8 month old battery was dipping into the 70s just a couple of weeks ago, but now, after I've used it on battery every other day, draining it completely before recharging, for a few weeks it has reached 89% and are still rising (hopefully even a few more notches ;)).

    Edit (after a re-read): The number of cycles are a bit high (one cycle is one complete discharge/recharge), so I would keep an eye on that, and if the number increases faster than expected I would contact Apple and ask if this is a battery or charger related problem...
  7. RoboCop001 thread starter macrumors 65816

    Oct 4, 2005
    Toronto, Canada
    Thanks for the replies.

    It hasn't really gone back up, except for those few times over the past couple of days that it went from 95 to 97 and back down to 95 again.

    But for the most part it's just been going down.

    It's charging now, and it says 95%. hmm...

    Maybe it'll eventually go back up to 100%?

    I don't want to have to buy a new battery so soon, but I suppose if there is something wrong with it, then I guess Apple might replace it.

    But it seems this could be a normal thing and that it'll go back up.

    If it's a good idea to charge it up when the computer warns about low battery, then I'll do that more often instead of charging it when it's not quite that low.
  8. bmcgrath macrumors 65816


    Oct 5, 2006
    London, United Kingdom
    Hmm strange. I see most of you people see it drop within the 90's%. For some reason i see it got down as far as 70% on my MBP but then goes back to 100% other times? Does anyone else see this? :confused:
  9. know-it-all5 macrumors 6502

    Jun 28, 2006
    My ibook g4 1.33ghz is 12months old and its at 97%
  10. bunnyagain macrumors newbie

    Dec 29, 2006
    Not exactly a good idea. Deep discharge or keeping a battery charged fully or almost are bad for health of lithium based battery. On the other hand, you need full discharge/charge to calibrate battery meter, but only "once in a while", like every month or something(depending how often you use your battery), since the calibration process itself is detrimental. For details, take a look at
  11. RoboCop001 thread starter macrumors 65816

    Oct 4, 2005
    Toronto, Canada
    Thanks for the link.

    So then it would be best to recharge it when it isn't almost all discharged? Like say at around.... 30-40%? Or even a bit higher?

    And then only occasionally let it go down very low (and all the way when calibrating every so often).

    Would running it off AC power be a good idea too? Not the whole time, though. I generally leave it plugged in for a while once it's fully charged. Or if I'm doing something processor intensive.
  12. aaron.lee2006 macrumors 65816


    Feb 23, 2006
    Ontario, Canada
    Yes I get this as well sometimes.
  13. Cybergypsy macrumors 68040


    May 16, 2006
    Central Florida!
    I had Apple replace mine..the second was sooooo much better.....
  14. bousozoku Moderator emeritus

    Jun 25, 2002
    Gone but not forgotten.
    I haven't seen the battery life estimator work correctly yet.

    I've had my PowerBook away from an electrical outlet quite a bit for about a week and it went from 35 cycles to 36 after charging it 3 times during that time and having it sleeping the most of the rest of the time.

    It did go to 100 % charge but now, it's stuck at 99 % and says "Battery is Charged" so I don't exactly believe it. It also mentioned over 4 hours of battery life which is completely unlikely with a system that might sometimes get 3.
  15. ghall macrumors 68040


    Jun 27, 2006
    Rhode Island
    After 2 months, my MacBook Pro was at 67%, and worked it's way back up to 96% in about a week. Now it's down to 88%.

    I record my battery capacity every week or so, with CoconutBattery, so I can say from expierience, the capacity fluctuates a lot. Best way to get it back up into the 90s is to use your computer on battery power until the computer goes into hibernation, then charge it up completly. I don't know if this matters, but after I plug it in, I shut it down, and don't turn it on until the battery is charged completly.

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