Apple today released Battery Update 1.3 which updates battery firmware and addresses battery performance issues with the 15-inch MacBook Pro. Your computer’s power cord must be connected and plugged into a working power source while running this update.
Battery Update 1.3 Requires:
• Mac OS X 10.4.10
• MacBook Pro (15-inch)
After the Battery Update has been installed, any additional batteries you put in your 15-inch MacBook Pro are automatically updated.
Battery Update 1.3 is available via Software Update and also as a standalone installer.
More info and download link (480KB) here.