About this replacement
Lenovo Yoga Slim 7 Carbon 14ACN6 — 7.72V Li-Polymer Replacement Battery (L20C4PF2)
This is a 7.72V, 7550mAh (58.29Wh) lithium-polymer cell for the Lenovo Yoga Slim 7 Carbon 14ACN6 series ultrabook. It replaces OEM part numbers L20C4PF2, L20D4PF2, L20M4PF2, and 8SSB11C66153. If your original cell has lost capacity, fails to hold charge, or the laptop won't run on battery at all, this is the direct swap.
- Yoga Slim 7 Carbon 14ACN6 compatibility: The 82L0 series shares a common battery bay footprint, connector pinout, and BMS handshake protocol across all regional variants — 82L0005BVN, 82L0005DGE, 82L0005RMX, and 82L0CTO1WW among them. The same L20-series cell seats and communicates identically across those SKUs.
- Bench tested on actual hardware: We ran charge and discharge cycles on this cell against the Yoga Slim 7 Carbon 14ACN6 platform. The BMS completed full charge handshake without error, charge termination triggered correctly at capacity, and the fuel gauge IC accepted the cell without throwing unknown device flags on the first cycle.
- Post-swap calibration on the 14ACN6: After installing this cell, run one full discharge to hibernate-cutoff — do not interrupt — 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 battery health as poor immediately after replacement
The Yoga Slim 7 Carbon's embedded controller reads cycle count and wear data stored in the old cell's EEPROM. When a new cell goes in, that data resets — the controller interprets zero cycles and mismatched charge history as a degraded or unknown cell. This is a firmware read issue, not a defect in the replacement battery. Running a full discharge-to-hibernate followed by an uninterrupted charge to 100% gives the BIOS one complete learn cycle. After one or two full cycles, the health indicator corrects itself.
Laptop shuts down at 20–30% charge shown on the gauge
This happens when the fuel gauge IC hasn't calibrated against the new cell's actual voltage curve yet. The gauge maps percentage to voltage thresholds learned from the old cell — when the new cell hits its own low-voltage cliff, the system cuts out before the displayed percentage reaches zero. It looks like a bad battery but it's a calibration gap. Run two to three full discharge-to-hibernate cycles without interruption. The fuel gauge IC recalibrates its curve against the new cell, and the shutdown point drops back to under 5% where it belongs.