Lenovo Backup Battery (Thinkpad T20/21/22/23) Single-use battery Lithium

The Lenovo Backup Battery for ThinkPad T20/T21/T22/T23 is a single-use 3V lithium battery designed to maintain CMOS settings and real-time clock operation in compatible ThinkPad laptops. It is intended as a direct replacement for the original backup cell and fits the specified T20–T23 series models.

Advantages

This single-use lithium backup battery delivers a stable 3V voltage, offering consistent preservation of BIOS/CMOS settings and clock data. It is supplied in the original form factor for ThinkPad T20–T23 models, which simplifies installation and ensures compatibility. The battery's construction supports long shelf life and reliable performance while the yellow-coloured casing helps with quick identification during replacement.

Suitable for

• Restoring or replacing the CMOS/RTC backup battery in Lenovo ThinkPad T20, T21, T22 and T23 laptops
• Repair and refurbishment of older ThinkPad T-series notebooks
• Maintaining BIOS settings and system clock during main battery removal or prolonged storage

Key specifications

• Battery type: single-use lithium cell
• Nominal voltage: 3 V
• Colour: yellow
• Compatible models: Lenovo ThinkPad T20, T21, T22, T23 series

How to use

Power down the laptop and remove any external power sources and the main battery before replacing the backup cell. Access the CMOS/backup battery compartment according to the service manual for your ThinkPad T20–T23 model, remove the depleted battery, and install the new 3V lithium backup battery in the same orientation. Reassemble the laptop and power it on; verify BIOS settings and correct system time.

Recommendations

Store the battery in a cool, dry place and avoid exposure to heat or moisture. Dispose of the used single-use lithium cell according to local battery disposal regulations. If unsure about disassembly, refer to official Lenovo service documentation or consult a qualified technician.