Cmos bios assembly battery (RTC Battery) are for Asus UX21a i3 2367M Asus UX21a i5 3317U Asus UX21e i3-2365M Asus UX21e i3-2367M Asus UX21e i5-2647M Asus UX21e i7-2677M Asus Ux21e-d UX21E-DH52 i5-2467M Cmos bios assembly battery (RTC Battery) is a cable harnessed 2 pin plug integration that is the power source to the rtc circuit enabling the motherboard to retain it's default settings ei: date, time and boot sequence. The renewal or replacement process might be something that can be somewhat challenging depending on the specific model of notebook, yet in most cases technical manuals will allow the scope of it's replacement process and allow owners to replace and renew the cmos battery. If in doubt, please ask us to assist or redirect you to that source help.
