Sony PCG-GRV680 VAIO User Guide - Page 6

Using the Battery Your computer, depending on the model you purchased, may come equipped with one battery bay and one multipurpose bay that supports a second battery. If your computer comes with two bays, you can purchase a second rechargeable battery to extend your computing time. For information on how to extend the life of the battery, see Conserving Battery Power for more information.  Inserting a battery  Removing a battery  Using a second battery  Locating battery information  Charging a battery  Notes on batteries  Frequently asked questions When operating your computer on battery power, your computer's CPU speed is reduced. The battery that comes with your computer is not fully charged at the time of purchase. The brightness of your computer screen automatically dims when you switch from AC power to battery power. To increase the brightness, press the Fn and F5 keys, and then press the Up Arrow or Right Arrow key. Page 6