I have a 3 month old MacBook 2.0GHz Core Duo. It is of week 38 batch of MacBooks, according to the serial #. I've been having a problem where if I use the laptop on battery power alone it will shut off at around 20%, without a Low-Battery warning message. There is no way to prepare for the shut off and I would lose work. That was the problem 1 week ago. I've taken it to the 'Genius' bar and they suggested I update to 10.4.8 from 10.4.7. I'd already had all the firmware updates. So I updated to 10.4.8 and now my laptop shuts off sooner than 20%. Sometime 23% and sometimes 30%. This isn't the Random Shutdown Syndrome of late as this happens ONLY when I'm running on battery.
I have uploaded a video to my YouTube page illustrating what is going on. There are 2 videos one showing what seems to be a Schizophrenic Battery and the other showing the MacBook shutting off. Here are the links:
Shutting off:
YouTube - MacBook Not RSS, Possible Defective Battery, Shuts Off
(note: In the long sections where nothings moving I've sped up the video in order for it to fit into YouTube's 10 minute limit.)
Schizophrenic Battery:
YouTube - MacBook Not RSS, Battery Spasms, Possible Defective Battery
The first video shows the MacBook actually shutting off at around 23% battery power. It seems the battery status is not accurate or possibly the battery is malfunctioning as it should be telling me that the laptop will Go to Sleep and that I should save my work before it does so. When it finally does shut off it doesn't go into Deep Sleep, which the Genius says it is doing. Why do I know this? Because you should be able to wake from deep sleep by pressing the keys, which is also what the Genius told me. I knew this already. I own a Pismo and iBook and I've never experienced this sort of problem. Also I know that it is not in Deep Sleep because if it is indeed in Deep Sleep why does it start up by pressing the Power Button? In the video, after it has shut off, I press the power button and the laptop starts up. (Indicating that it was indeed, off.) But shortly after starting up, it shuts off again, indicating that the battery is indeed out of juice.
I plug in to some power and start up again only to find that the battery power is in fact still at 24%. If the battery was dead then why is there still a charge left? I think the battery is malfunctioning. What do you think?