Strange battery behavior?

Discussion in 'General Mac Discussion' started by answer348, Aug 26, 2004.

  1. answer348 macrumors member

    Jul 25, 2004
    I've had my powerbook G4 for about a week now and since the day I got it I've had the battery power show as a percentage. When I first starting using it, it would charge till the adapter glowed green and show 100%. The next day fully charged it showed 99%. That soon became 95%, and now it wont rise above 94%. Is this normal?
  2. C-Mezak macrumors regular


    Jul 14, 2004
    Edinburgh, Scotland
    Did you properly callibrate your battery during this first week? If not, I think the prescribed action is to reset the powere management unit (PMU) by shutting down your powerbook and holding ctrl-apple-shift as you restart it. Then, run the machine until the battry is drained and it goes to sleep. Once it goes to sleep, charge it all the way back up.

    That oughtta help
  3. answer348 thread starter macrumors member

    Jul 25, 2004
    I calibrated it the first day, or at least I thought I did. It was either 100% or 99% at that point.
  4. stoid macrumors 601


    Feb 17, 2002
    So long, and thanks for all the fish!
    Make sure that you always plug the adapter into the wall/socket before plugging it into your laptop!
  5. ChrisFromCanada macrumors 65816


    May 3, 2004
    Hamilton, Ontario (CANADA)
    That is completely normal, all apple laptops suffer from this. If you leave it plugged in after is has become fully charged it will drain very slowly. Maybe someone else could go into some detail about why this happens.
  6. abhishekit macrumors 65816


    Nov 6, 2003
    akron , ohio
    It decreased from 99 to 95 while you had it plugged in?? thats certainly not good. But may be, the power cord was just loose.
    As per as why it wont rise above 94% is because in between 94-99, the charging stops. This is to save your battery. Every battery has a fixed number of recharge cycles. So this mechanism prevents short recharge cycles and saves your battery. If you let it drain upto 90%, you would see that it would again start charging.
    Many times fully charged it would show 99%, because of some losses while you put it to sleep or something. But anyways it stays at that value, and its very normal.
    hope it helps.

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