I am sorry for responding late. CMOS battery on this system is 6V and if you are considering replacing the battery, the part # is 2M728. You may contact sales department for assistance. Let me know the region you belong to, to provide the contact information.
Thanks for your reply. I'm sorry, but I am still a bit confused. I find several vendors selling this part number (2M728) online, many even indicate it is for my X200. But all these vendors list it as 4.8 volts. You said it is 6 volts. Either several vendors are all wrong, or someone has given you incorrect information. I apologize for the inconvenience, but can you please double-check the voltage of this part?
Thanks again for your help!
I double checked and this battery as per Dell internal tools is 6 volts. I am not very sure about the other vendors specifications.
You may also check this link: