CMOS battery removal and installation - ThinkCentre A50, S50
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.
To change the battery
Turn off the computer and disconnect the power cord from the electrical outlet and from the computer.
Disconnect all other cables attached to the computer.
Remove the PCI riser and PCI adapters that impede access to the battery.
Remove the old battery.
Install the new battery.
Install the PCI riser and adapters if removed.
Replace the cover, and connect the cables. See "Cover installation and connecting the cables". Note: When the computer is turned on for the first time after battery replacement, an error message might be displayed. This is normal after replacing the battery.