Battery is always at 99%

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Battery is always at 99%

I have a MacBook Pro 2.0GHz (Rev. A) and the battery "always" at 99%. Switching to see time remaining reports the correct time but the percentage is always 99%. I downloaded coconutBattery and it reports that the battery is fully charged. I drained the battery until the MBP turned off, plugged the AC adaptor and when I started the computer battery was at 99% again. I tried reseting the SMC unit (remove battery/AC adaptor and press and hold power button for 5-10secs) and that didn't fix it. Zapping firmware didn't help either. I created a new user account and it also reports 99%. I'm thinking of reinstalling Mac OS X but I don't think that will solve the problem. Also, the charge level LEDs on the battery itself always report full charge. Any ideas?
(Running 10.4.8)

MacBook Pro 2.0GHz 1.5GB RAM (Rev A) Mac OS X (10.4.8)

Posted on Nov 13, 2006 1:24 PM

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Answer 1

Nov 13, 2006 1:38 PM in response to Khaled

Do not bother reinstalling the system. I have gone through three powerbooks under OS X and rarely does it "say" 100%. It's annoying but I just live with this bug.

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Answer 2

Nov 13, 2006 1:48 PM in response to Khaled

Do I understand that your battery reports 99% even when it is drained?

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Answer 3

Khaled Author

Level 1

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Nov 13, 2006 8:02 PM in response to Richard.Taylor

yes, it is always at 99% and then when it is drained the MBP dies. I downloaded and installed firmware updater 1.2 released today and according to coconutbattery my max battery charge is 1196mAh instead of 5500mAh or so. So I'm trying to calibrate my battery and see if that works.

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Answer 4

Nov 14, 2006 10:53 AM in response to Khaled

Check this article out.

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Answer 5

nerowolfe

Level 6

13,090 points

Nov 15, 2006 9:03 AM in response to Khaled

Yes, a battery calibration might help.
You might also consider resetting the PRAM and NVRAM
http://docs.info.apple.com/article.html?artnum=2238

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Answer 6

Khaled Author

Level 1

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Nov 15, 2006 4:15 PM in response to nerowolfe

hey all,

thanks for all the input, sadly the problem still presists. My MBP thinks the battery is always 99%. I reset PRAM, drained the battery and recharged it (following the battery callibration KB article), repaired permissions, ran all periodic maintenance script, used the hardware test DVD, trashed preferences files and still, battery is always 99% even if it is drained totally. couldn't reset NVRAM tho because it is intel and doesn't use the same old open firmware. I plan to call Apple tomorrow since my machine is still under warranty, but, why bad things happen to nice Macs?

thanks all

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