[NUC] CMOS Battery on the NUC

A coin-cell battery (CR2032) powers the real-time clock and CMOS (complementary metal-oxide-semiconductor) memory. The battery has an estimated life of three years when your NUC isn't plugged into an AC power source. When the computer is plugged in, the standby current from the power supply extends the life of the battery. The clock is accurate to ±13 minutes/year.

The CMOS battery is connected to an onboard header on the processor side of the board by a 1x2 connector (Molex 51021-0200).

Example of battery location:

 

Notes
  • The location of the battery varies depending on the NUC model.
  • ASUS does not provide battery replacements. CR2032 batteries with a wire and Molex connector may not be locally available.
  • To find a replacement, search the Internet for CR2032 with wire or CR2032 with Molex connector and purchase through an online retailer.

If the battery and standby current both fail:

  • Date and time values in BIOS might not be accurate.
  • The error message CMOS Battery Low appears when the computer starts.

Follow these steps to replace the CMOS battery:

  1. Disconnect the power cord from the computer or the AC power source (electrical outlet or power adapter).
  2. Disconnect all peripheral devices attached to the NUC.
  3. Remove the bottom chassis cover.
  4. Remove the board from the chassis to access the battery on the processor side of the board.
  5. Unplug the battery wires from the onboard connector and remove the battery. 
  6. To install the new battery:
    1. Remove the paper backing from the battery adhesive pad.
    2. Place the battery onto the board next to the thermal solution. As seen in the image above. 
    3. Connect the wires to the battery connector.
  1. Reinstall the board in the chassis.
  2. Replace the chassis cover.
Caution 
Caution
  • The battery is located on the underside of the motherboard in most NUC models. Take care when removing the motherboard from the chassis to prevent board damage.
  • Electrostatic discharge (ESD) can damage components. Apply the procedures described here only at an ESD workstation using an anti-static wrist strap and a conductive foam pad. If a station isn't available, create some ESD protection by wearing an anti-static wrist strap attached to a metal part of the chassis.

 

To find the MSDS certificate for the CMOS Battery, choose your NUC in the "Regulatory certificates and declarations for NUC" section of the Regulatory Information Index for NUC.

Related topic
Technical Product Specifications for NUC Products