CMOS BIOS battery Dell ML-1220 3V Lithium (for W6NPD) replacement cell

Replacement CMOS/BIOS battery Dell ML-1220 is a 3V lithium coin cell designed to maintain motherboard BIOS settings and the real-time clock when the main power source is removed. Compatible with systems that use the original W6NPD cell, this replacement provides a compact power solution for desktop and server motherboards during transport, storage, or after power loss. The cell is intended for straightforward in-system replacement and for use in maintenance, repair or refurbishment of compatible Dell systems.

Advantages

The ML-1220 3V lithium cell offers stable voltage output and a long shelf life, reducing the need for frequent replacements. Its standardized coin-cell size ensures a secure fit in compatible motherboard holders. The battery's chemistry provides reliable low-drain performance suitable for maintaining CMOS memory and clock functionality over extended periods without external power.

Suitable for

• Replacing depleted CMOS/BIOS batteries on compatible Dell motherboards
• Motherboard maintenance and refurbishment projects
• Repairing systems that fail to retain BIOS settings or correct system time
• Storage or transport of systems where BIOS and clock preservation is required

Key specifications

• Nominal voltage: 3 V
• Chemistry: lithium manganese dioxide (Li-MnO2) coin cell
• Form factor: coin/button cell (ML-1220 size)
• Intended use: low-drain devices for CMOS/BIOS memory and real-time clock backup
• Typical shelf life: long-term storage stability (years under proper conditions)
• Operating temperature range: suitable for typical indoor electronics use

How to use

Power off the system and disconnect it from mains power before attempting battery replacement. Locate the CMOS battery holder on the motherboard and carefully remove the depleted cell according to the board manufacturer's instructions, taking electrostatic discharge precautions. Insert the replacement ML-1220 3V cell with the correct polarity, ensuring it is seated securely in the holder. Reconnect power and verify BIOS settings and system clock; restore any custom BIOS configuration if necessary.

Usage recommendations

Store unused cells in a cool, dry place away from direct sunlight and heat sources. Do not recharge, disassemble, short-circuit, or expose the cell to fire. Dispose of spent batteries according to local regulations for lithium battery recycling or hazardous waste. For safe installation, consult the motherboard manual and, if unsure, seek professional service to avoid damage to the board or loss of data.