09-20-2017 05:33 AM
HMM does not document a CMOS battery.
09-20-2017 06:14 AM - edited 09-20-2017 06:15 AM
In addition, if you are referring to the RTC battery (real time clock battery) using example motherboard part number 5B20G45454 (MB L Z50-70 W8S 4510 GM 2G) blue coin cell battery onboard shown below image:
Here is also the service training module for added reference.
Hope this helps answer your query.
** edit note: added service module