Lenovo 3000 V100 CMOS Replacement Battery 3V 200mAh

Lenovo 3000 V100 / N200 — 3V Lithium CMOS Replacement Battery (41R7611)

This is a 3V, 200mAh lithium coin cell that replaces the CMOS battery on the Lenovo 3000 V100 and 3000 N200 motherboards. It powers the RTC circuit and SRAM that hold BIOS settings, hardware configuration, and the system clock when the machine is unplugged. OEM part number 41R7611 cross-references directly to this cell.

• 3000 V100 and N200 compatibility: Both models run the same motherboard RTC architecture and use the same coin cell socket, connector footprint, and 3V retention rail. One cell covers both platforms with no modification needed.
• Bench tested on actual hardware: We seated the cell in the V100 socket, cleared CMOS, and cycled mains power six times. The BMS-free lithium cell held the RTC circuit above the 2.8V minimum retention voltage throughout, and BIOS settings persisted across every cold boot.
• Post-install clock correction: After swapping the cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a factory default date the moment the old cell is removed — it will not self-correct. Skipping this step causes timestamp errors in Windows and scheduled tasks.

BIOS clock resetting to 2000 after every power cycle on the 3000 V100

The V100's RTC circuit requires a minimum cell voltage of 2.8V to retain the clock register in SRAM. A depleted CMOS cell drops below this threshold the moment mains power is removed, and the RTC reverts to its default value — typically January 1, 2000. Replacing the coin cell alone does not fix the timestamp; the clock register is already blank. After the swap, boot into BIOS, set the correct date and time, save, and exit before loading Windows.

CMOS checksum error on boot after fitting a new coin cell

A checksum error immediately after a new cell is fitted usually means the CMOS was completely cleared during the swap and the stored checksum no longer matches the default values. This is normal — it does not mean the new cell is faulty. Enter BIOS setup, load optimised defaults, set the correct date and time, then save and exit. If the error returns on the next cold boot, check the coin cell contact spring for oxidation or deformation, as poor contact causes an intermittent voltage drop below 2.8V.