Do not open your computer or attempt any repair before reading and understanding the "Important safety information" in the ThinkCentre Safety and Warranty Guide that came with your computer. To obtain a copy of the ThinkCentre Safety and Warranty Guide, go to:http://www.lenovo.com/support
Your computer has a special type of memory that maintains the date, time, and configuration information for built-in features. The battery keeps this information active when you turn off the computer.
The battery normally requires no charging or maintenance throughout its life; however, no battery lasts forever. If the battery fails, the date, time, and configuration information, including passwords, are lost. An error message is displayed when you turn on the computer.
Before performing the following procedure, be sure to read and understand the information about replacing and disposing of the battery in the "Batteries" and "Lithium battery notice" sections of the ThinkCentre Safety and Warranty Guide.
To replace the battery, do the following:
Remove all media from the drives and turn off all attached devices and the computer. Then, disconnect all power cords from electrical outlets and disconnect all cables that are connected to the computer.
Turn on the computer and all attached devices. Note: When the computer is turned on for the first time after replacing the battery, an error message might be displayed. This is normal after replacing the battery.