Apple has recalled certain lithium ion rechargeable batteries that were sold worldwide from October 2004 through May 2005 for use with the following notebook computers: 12-inch iBook G4, 12-inch PowerBook G4, and 15-inch PowerBook G4. The affected batteries could overheat, so Apple has asked that all owners of these models, as well as those who purchased replacement or extra batteries, stop using them at once and order a free replacement battery (or batteries) immediately. Once you have removed the battery, you can still plug in the AC adapter to power the computer. If you must temporarily use your computer with the battery, Apple urges users to not leave it unattended and check for signs of overheating.
