Attention
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 the Lenovo Support Website.

Your computer has a special type of memory that maintains the date, time, and settings for built-in features, such as parallel-port assignments (configuration). A 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.

Refer to the "Lithium battery notice" in the ThinkCentre Safety and Warranty Guide for information about replacing and disposing of the battery.

To replace the battery, do the following:

1. Turn off the computer and disconnect all power cords from electrical outlets.
2. Open the computer cover. See "Opening the computer cover".
3. Locate the battery. See "Locating parts on the system board".
4. Remove the old battery.

5. Install a new battery.

6. Close the computer cover and connect the cables. See "Completing the parts replacement".
   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.
7. Turn on the computer and all attached devices.
8. Use the Setup Utility program to set the date, time, and any passwords. See "Using the Setup Utility program".
9. Go to "Completing the parts replacement".