I just acquired an old clamshell iBook link, and my friend told me that when he had got it a few months ago that the battery had been rather new, and he was getting 3-4 hours of life from it. I did the terminal command to show battery capacity and it initially showed 2750 mAh. Once the battery was fully charged I set out to find out how long it would last under my normal use. Everytime I've run it off battery, when the battery gets down to 50-70% it jumps to zero and the iBook goes to sleep. Each time I've retested the battery and have gotten increasingly depressing results. The progression is as follows: initial: 2750mAh 1st recharge: 2494mAh 2nd recharge: 2238mAh 3rd recharge: 1982mAh 4th recharge: 1726mAh 5th recharge: 1470mAh 6th recharge: 1214mAh 7th recharge: 958mAh The iBook is running the latest version of Tiger 10.4.4 and has all other software up-to-date according to Software Update.