About this replacement
IBM ThinkPad X60 / X61 Series — 14.4V Li-ion Replacement Battery (40Y7001)
This 14.4V, 2200mAh (31.68Wh) Li-ion battery replaces IBM part 40Y7001 and its FRU equivalents. It fits the ThinkPad X60 and X61 family — compact mid-2000s business notebooks that share the same battery bay, connector, and BMS communication protocol. Install it when the original cell no longer holds charge or the laptop won't run off AC disconnect.
- X60 and X61 shared battery platform: Lenovo carried the X60 battery spec directly into the X61 revision — same 14.4V rail, same 8-pin SMBus connector, same BMS handshake. One cell fits both generations without adapters or firmware changes.
- Bench tested on actual hardware: We cycled this cell on an X60 1702 chassis. The BMS negotiated correctly over SMBus on first insertion, reported state-of-charge without error, and charge termination triggered cleanly at full capacity.
- ThinkPad battery learn cycle after install: After fitting, run the laptop on battery until it hibernates at cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.
BIOS reporting poor battery health immediately after fitting a new cell
The ThinkPad BIOS reads health status from EEPROM data stored in the battery's BMS chip. A new cell ships with factory EEPROM values that don't match the laptop's learned baseline, so the BIOS flags it as degraded even though the cell is new. This is a data mismatch, not a hardware fault. Run one full discharge-to-hibernate then a full uninterrupted charge — the BIOS recalibrates against the new cell's actual figures and the health warning clears.
Laptop shuts down abruptly while the OS gauge still shows 20–25% remaining
This happens when the fuel gauge IC hasn't calibrated to the new cell's voltage curve. The old calibration data expects a gradual voltage taper, but the new cell hits its low-voltage cutoff at a different point — so the reported percentage and the real remaining capacity diverge. Under full CPU and display load, the cell reaches cutoff voltage before the gauge reaches zero. Two full discharge-and-charge cycles sync the fuel gauge IC to the new chemistry; after that, shutdowns should align with the gauge reading below 5%.