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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 replace the CMOS battery, you must reconfigure the server and reset the system date and time.

When replacing the lithium battery, use only Lenovo specified part number or an equivalent type of battery recommended by the manufacturer. If your system has a module containing a lithium battery, replace it only with the same module type made by the same manufacturer. The battery contains lithium and can explode if not properly used, handled, or disposed of.

Do not:
  • Throw or immerse into water
  • Heat to more than 100°C (212°F)
  • Repair or disassemble

Dispose of the battery as required by local ordinances or regulations.

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.
  • Read Installation Guidelines and Safety inspection checklist to ensure that you work safely.

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

  • 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. Install any parts you removed and connect the cables.
  2. 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.
  3. Install the CMOS battery. Ensure that the CMOS battery is seated in place.
    Figure 1. CMOS battery installation
    The positive and negative ends of the CMOS battery


    Before you install the CMOS battery from or into the socket, differentiate between the positive and negative ends. Use the illustration above for guidance.

    CMOS battery installation


    Before you install the battery into the socket, make sure that the positive side faces upward.

    1. Tilt the battery and insert it to the positive end on the socket, and make sure that the battery goes tight to the metal clip.

    2. Press the battery down until it clicks into the socket.

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.

Demo video

Watch the procedure on YouTube