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?