What do most of you folks do? Per step 5 of the following instructions . . . Is it better to simply "turn off" the computer or "allow it to sleep for 5 hours or more"? It appears that most people choose to let their computers sleep for some 5 hours. Is that the better choice to calibrate a battery properly. In searching, I haven't found where someone has just shut their computer down and then recharge the battery. PowerBook G4 (15-inch Double-Layer SD), MacBook (all models), MacBook Pro (all models), MacBook Pro (17-inch) (all models) and MacBook Air The battery calibration for the PowerBook G4 (15-inch Double-Layer SD) and any model of MacBook or MacBook Pro has been updated because of a new battery released with this computer. With these computers, follow these steps to calibrate your battery: 1. Plug in the power adapter and fully charge your PowerBook's battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged. 2. Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in. 3. Disconnect the power adapter with the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, you will see the low battery warning dialog on the screen. 4. Continue to keep your computer on until it goes to sleep. Save all your work and close all applications when the battery gets very low, before the computer goes to sleep. 5. Turn off the computer or allow it to sleep for five hours or more. 6. Connect the power adapter and leave it connected until the battery is fully charged again.