About this replacement
Lenovo ThinkPad X1 3rd Gen Tablet — 7.72V Li-Polymer Replacement Battery (01AV454)
This 7.72V, 5050mAh (38.99Wh) Li-Polymer battery replaces the original pack in the Lenovo ThinkPad X1 3rd generation tablet. It matches the OEM voltage rail, connector, and BMS handshake required by this device. Fits models using part numbers 01AV454, L16L4P91, L16M4P91, L16S4P91, SB10K97599, SB10T83162, and 5B10W13919.
- ThinkPad X1 3rd Gen platform fit: All variants of the X1 3rd Gen tablet share the same 7.72V two-cell Li-Polymer pack, connector pinout, and BMS communication protocol. Swapping to a different voltage or connector layout will trigger an immediate BMS rejection at boot.
- Bench tested on actual hardware: We ran this cell on a ThinkPad X1 3rd Gen unit and confirmed the BMS handshake completed without error codes, charge current ramped correctly through the CC/CV stages, and no cell-mismatch flags appeared in the Lenovo power management interface.
- Fuel gauge recalibration after swap: After installing this battery, run one full discharge to automatic shutoff, then charge uninterrupted to 100% without using the device. This resets the fuel gauge IC calibration against the new cell and clears the inaccurate percentage readings that typically appear in the first few cycles after a replacement.
ThinkPad X1 tablet shutting down at 15–25% remaining
The X1 3rd Gen runs a high-resolution display alongside simultaneous WiFi and LTE activity, which creates a combined load spike that can pull the cell voltage below the BMS cutoff threshold before the reported percentage reaches zero. The fuel gauge IC maps voltage to percentage using a discharge curve calibrated to the old cell — a new cell with a different internal resistance will cause the curve to misalign. The BMS then cuts power at what the software still reads as 15–25%. One full uninterrupted discharge-to-shutoff cycle followed by a full charge resets that curve and resolves the early cutoff.
Fast charging not available after battery swap on the X1 tablet
The ThinkPad X1 3rd Gen uses USB-PD negotiation to unlock higher charge rates — the charge IC and BMS must complete one accepted charge cycle on the new cell before the firmware permits full USB-PD current. On a fresh install, the system defaults to a conservative charge rate as a safety measure. Plug into the original Lenovo USB-PD adapter, let the battery charge fully without interruption, and fast charging will be available from the next session. Using a third-party or low-wattage adapter for that first cycle will delay this unlock.