Skip to main content

Install the CMOS battery

Use this information to install the CMOS battery.

About this task

The following tips describe information that you must consider when installing the CMOS battery.
  • Lenovo has designed this product with your safety in mind. The lithium CMOS battery must be handled correctly to avoid possible danger. If you replace the CMOS battery, you must adhere to local ordinances or regulations for battery disposal.
  • If you replace the original lithium battery with a heavy-metal battery or a battery with heavy-metal components, be aware of the following environmental consideration. Batteries and accumulators that contain heavy metals must not be disposed of with normal domestic waste. They will be taken back free of charge by the manufacturer, distributor, or representative, to be recycled or disposed of in a proper manner.
  • To order replacement batteries, call your support center or business partner. For Lenovo support telephone numbers, see Support Phone List for your region support details.

After you install the CMOS battery, you must reconfigure the server and reset the system date and time.
  • Read Installation Guidelines to ensure that you work safely.

  • Power off the server and disconnect all power cords for this task.

    disconnect all power
    The power-control button on the device and the power switch on the power supply do not turn off the electrical current supplied to the device. The device also might have more than one power cord. To remove all electrical current from the device, ensure that all power cords are disconnected from the power source.
  • Prevent exposure to static electricity, which might lead to system halt and loss of data, by keeping static-sensitive components in their static-protective packages until installation, and handling these devices with an electrostatic-discharge wrist strap or other grounding system.


  1. Touch the static-protective package that contains the CMOS battery to any unpainted surface on the outside of the server. Then, take the CMOS battery out of the package.
  2. Install the CMOS battery. Ensure that the CMOS battery is seated in place.
    Figure 1. CMOS battery installation
    CMOS battery installation

After you finish

  1. Complete the parts replacement. See Complete the parts replacement.

  2. Use the Setup utility to set the date, time, and any passwords.
    After you install the CMOS battery, you must reconfigure the server and reset the system date and time.

Demo video

Watch the procedure on YouTube