About this replacement
Lenovo ThinkPad X13 Yoga G2 — 11.58V Li-Polymer Replacement Battery (5B11A13107)
This 11.58V, 4500mAh (52.11Wh) lithium-polymer cell replaces the internal battery in the Lenovo ThinkPad X13 Yoga G2 convertible laptop. It fits all X13 Yoga G2 variants, including the 20W8000TGE, 20W8001JCK, and 20W8001WAU, among 49 additional sub-models. Cross-references include OEM part numbers 5B11A13107, 5B11M90077, L20M3P71, and SB11A13105.
- X13 Yoga G2 platform fit: All X13 Yoga G2 variants share the same 11.58V three-cell Li-Polymer configuration, connector pinout, and BMS communication protocol — so one cell covers the full model spread without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a ThinkPad X13 Yoga G2 unit. The BMS handshake completed correctly, charge termination triggered at full capacity, and the fuel gauge IC reported the correct Wh rating in Lenovo Vantage after two calibration cycles.
- Post-install calibration step: After fitting, run the laptop down to hibernate cutoff on a real workload — not idle — 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.
BIOS reporting poor battery health immediately after replacement
ThinkPad firmware stores battery health data in the EEPROM of the original cell. When a new cell is fitted, the BIOS reads no prior cycle history and flags the battery as degraded or unknown — this is a firmware artefact, not a fault with the replacement. The fix is a full battery learn cycle: discharge to hibernate, then charge to 100% without interruption. After one to two full cycles, the BIOS recalibrates its health estimate against the new cell's actual voltage curve and clears the warning.
Laptop shuts down at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet mapped the new cell's voltage-to-capacity curve. The old cell's discharge profile is still cached, so the reported percentage does not match the actual cell voltage — the laptop hits the low-voltage cutoff while the gauge still shows charge remaining. Run two full discharge-to-hibernate cycles to force the IC to recalibrate against the new chemistry. After calibration, the shutdown threshold aligns with the displayed percentage, and the gauge stabilises at roughly 3.0V per cell at the true cutoff point.