Macbook Air (2008) shuts down on its own at ~20%

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Macbook Air (2008) shuts down on its own at ~20%

Hi! I recently purchased a used Macbook Air and am running OSX Mountain Lion on it. I absolutely love it, but there's one problem: when the battery gets close to or down to 20%, it shuts down without warning, much as if I'd shut it down myself, except sudden. I've tried resetting my SMC--in fact, my bluetooth messed up and I did it to fix that--but it hasn't helped. I've only ever seen a battery warning once, when it got to 9%. Does anyone know how to reset the battery warning (to, say, 25%) or fix/recalibrate the battery to act properly and not shut down at 20%? Thank you, everyone, for your help in advance.

-Nova

MacBook Air, OS X Mountain Lion (10.8.4)

Posted on Jul 25, 2013 10:12 AM

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Answer 1

dalstott

Level 4

2,639 points

Jul 25, 2013 10:15 AM in response to tnm_nova

A 2008 MBAir that has been used probably needs a new battery. The shutting down prematurely is a sign of this. If you have an Apple service provider or Apple Store you should let them test it and replace.

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Answer 2

tnm_nova Author

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Jul 25, 2013 10:18 AM in response to dalstott

The battery says it's okay, but I was considering something of the same. I have a MBA battery in my Amazon cart ready to go, if I can't find another way to fix it.

Here's the stats off of my machine re: the battery:

Battery Information:

Model Information:

Serial Number: 9G85206C113DB

Manufacturer: DP

Device Name: bq20z951

Pack Lot Code: 0

PCB Lot Code: 0

Firmware Version: 002a

Hardware Revision: 5

Cell Revision: 100

Charge Information:

Charge Remaining (mAh): 1770

Fully Charged: No

Charging: Yes

Full Charge Capacity (mAh): 3413

Health Information:

Cycle Count: 514

Condition: Normal

Battery Installed: Yes

Amperage (mA): 2040

Voltage (mV): 11752

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Answer 3

tnm_nova Author

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Jul 25, 2013 10:19 AM in response to dalstott

Lol and re: the Apple store/service provider: Apple doesn't believe in WV XD There's nothing closer to me than in PA or OH.

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Answer 4

dalstott

Level 4

2,639 points

Jul 25, 2013 10:46 AM in response to tnm_nova

Anything above 300 cycles is gravy. see this link.

http://support.apple.com/kb/ht1519

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Answer 5

tnm_nova Author

Level 1

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Jul 25, 2013 6:37 PM in response to tnm_nova

I actually have the aluminum MBA from late 2008, but even still, my battery is over cycle count for that model (500). So probably the best to get a new battery. Thank you! It's nice to have that link, by the way. Thanks a lot for your help.

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Answer 6

dalstott

Level 4

2,639 points

Jul 26, 2013 4:35 AM in response to tnm_nova

You are welcome. You can replace the battery yourself with a few tools. This link is to an illustrated how to do it page.

http://www.ifixit.com/Guide/Installing+MacBook+Air+Models+A1237+and+A1304+Batter y/848/1

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