Hey guys, I just bought a new clamshell battery for my iBook, as the old one wouldn't hold a charge. It powers up just fine, the estimate of 2 1/2 hours sounds about right, and everything goes smooth until the battery hits the 30% mark. The computer just shuts off. Doesn't shut down, shuts OFF. Like you pulled the battery out. When I plug it into the wall immediately following the "death", it boots up and begins charging, starting at 0%. Does this mean that the battery actually is at 0% when it says 30%? So Mac OS X doesn't know to sleep? Is there a way to manually re-calibrate? I've tried letting it start at 0% and charge up to 100% while staying awake, and have let it wear down until it does, but to no avail. Any suggestions please?