Macbook Pro Battery Dying?

[thefoo]

OS: 10.4.11
Model: 15" 2.4Ghz 2GB

Basically I'm running on battery, 74% life remaining and the laptop loses power without warning.

I press the power button, it starts to boot but powers off again during the spinner.

I plus in the power cable and start her up fine. Shows 74% remaining. Take out the power cable again. I work to 70% remaining, and the power goes off again without warning.

Rinse and repeat when I get down to 68%.

If I turn over the laptop and press the button on the battery three of the five lights show.

Normal use is on my desk at home so usually plugged in and no calibrated frequently but then it never normally complains when it gets down to low power anyway. Only recently it has begun exhibiting this fault.

The laptop was bought last August from a retailer giving two year warrantees as standard and I'm expecting delivery of the Applecare contract shortly. Question is, what is wrong?

I have done the shutdown then press power for five seconds without any changes to behaviour.

Any ideas?

 

[merl1n]

I have done the shutdown then press power for five seconds without any changes to behaviour.

You are referring to an SMC reset. When you did this, did you have the battery out of the computer? If not, you did not do an SMC reset.

Disconnect power, remove the battery, press the power button for 5 seconds, insert the battery and hook up external power.

Did you ever calibrate the battery?

http://support.apple.com/kb/HT1490

If so, do it again.

 

[thefoo]

An update to this.

Firstly, yes shortly after purchase the battery was calibrated however not in recent months admittedly. Might an poorly calibrated battery give such wildly inaccurate readings?

Second, with a fully charged battery I cut the power and watched it drop to 80% before the power died without warning. So I plugged it back in and powered her up once again.

Then I shut her down (properly) to perform a PVRAM reset which I believe was successful. At least, I booted her, pulled the power lead and when it dropped to 80% I got told I was now at 25% and needed to save my work before the battery drained further. It lasted about 7-8 minutes before power was completely lost. Yes that's right, it went from 80% to 25% in the blink of an eye.

Now of course I'm in the position that it could be calibrating while switched off however I kind of need the laptop. So here's a question:

Can the calibration occur (the 5hrs+ bit at the end) with the battery removed? That's how I'm working at the moment.

If this doesn't fix it I might have to call Apple...

 

[merl1n]

I'd suggest you do this at the end of the day and let the computer sleep overnight with the battery in. I don't know if there is interaction with the battery and the SMC during this 5 hour period.

You can call Apple to verify.