What is CMOS battery
This battery allows the BIOS to maintain settings on the computer. These settings include recognizing hard drive settings�� USB on-board device settings and keeping your system clock on time. Usually�� the first visible sign that you need to replace the CMOS battery is that your laptop clock keeps losing time. A CMOS battery can last from three to five years.


Compatible with:

IBM Thinkpad 570 Series -- 570  570E  570X  570Z 
IBM ThinkPad A Series -- A20  A20P  A20M  A21  A21E  A21M  A21P  A22 A22M  A22P  A23  A30 A30P  A31P 
IBM ThinkPad T Series -- T20  T21  T22  T23  T30  T40   T60 
IBM ThinkPad R Series -- R40  R40e  R50  R50e  R50p  R51  R52  R60 
IBM ThinkPad X Series -- X30  X31  X32 
IBM xSeries -- 300  400 
 
P/N: 02K6541  02K7087  02K7075  08K8050 


Package : One pcs of Real Time Clock (RTC) CMOS Battery .