About this replacement
IBM ThinkPad R60 Series — 10.8V Li-ion Replacement Battery (40Y6797)
This is a 10.8V, 4400mAh (47.52Wh) Li-ion battery for the IBM ThinkPad R60 notebook. It fits the R60 9455, R60 9456, R60 9457, and dozens of other R60 variants. It replaces OEM part numbers including 40Y6797, 40Y6798, 92P1131, 92P1138, and related FRU and ASM codes.
- ThinkPad R60 series fit: The full R60 lineup shares a common battery bay geometry, connector pinout, and BMS handshake protocol. That is why a single cell covers all sub-models from the base R60 through the 9455, 9456, and 9457 variants — same voltage rail, same communication lines, same latch mechanism.
- Bench tested on actual hardware: We ran this cell on an R60 9455 unit. The BMS negotiated correctly on first insertion, BIOS recognised the pack without error, and charge current ramped normally through CC and CV phases to the full 10.8V endpoint.
- Post-swap calibration on the R60: After installing, run one full discharge to the hibernate 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 ThinkPad firmware.
Why the R60 BIOS reports poor battery health immediately after a cell swap
The ThinkPad BIOS reads health data from the battery's EEPROM, not from live voltage alone. When a new cell arrives, its EEPROM charge cycle count and wear data do not match the laptop's stored baseline, so the firmware flags the pack as degraded. This is a data mismatch, not a fault with the cell. Running the battery learn cycle — one full discharge to hibernate, one uninterrupted charge to 100% — rewrites the baseline and clears the warning.
ThinkPad R60 shutting down at 20–30% charge shown on screen
The fuel gauge IC estimates remaining capacity based on voltage curves calibrated to the original cell. After a swap, those curves are stale, so the gauge reads 25% while actual cell voltage has already crossed the low-voltage cliff under full CPU and display load. The laptop shuts down to protect the cell even though the percentage looks safe. Run two full discharge-to-hibernate and charge-to-100% cycles — this forces the fuel gauge IC to recalibrate its voltage-to-capacity map against the new cell chemistry, and the shutdown threshold will track accurately from cycle three onward.