Cmos Bios RTC Battery fits as a replacement for a Varta CR2032-58A2 that's standard equipment to a Dell Alienware X51 R2 Andromeda. which will also work on system board repairs associated with date and time settings, a replacement to the Cmos bios battery (RTC Battery) found on which are serviced with a 2 pin Connector Plug RTC Battery Assembly. ie: yellow KTS CR2032 or Varta CR2032-58A2. (Compatible Model, not oem ) The cmos bios battery being offered here are based on a 3 volt 210mah rating system board need, where what is required is a cable and 2 pin plug. 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.