BL271 Lenovo ZUK Edge Replacement Battery 3.85V 3000mAh

Lenovo ZUK Edge — 3.85V Li-Polymer Replacement Battery (BL271)

The BL271 is a 3.85V, 3000mAh Li-Polymer cell that fits the ZUK Edge (Z2151), ZUK Edge Premium Edition, and ZUK Edge Premium Edition TD-LTE Dual SIM. Dimensions are 76.68 × 63.36 × 3.34mm — matching the original cell footprint in the chassis. Capacity is 11.55Wh as rated.

• ZUK Edge and Z2151 fitment: The Z2151 board family runs a single battery connector pinout with an integrated NTC thermistor line. All variants listed here — including the TD-LTE dual-SIM model — share that same connector, BMS handshake voltage, and physical cell cavity dimensions.
• Bench tested on actual hardware: We cycled this cell on a Z2151 board, monitored BMS charge termination, and confirmed the protection circuit trips correctly at over-voltage and under-voltage thresholds. Charge acceptance was clean across both standard and fast-charge paths after the first full cycle.
• First-cycle fast charge handling on the ZUK Edge: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate its discharge curve against the new cell before high-current fast charging pushes current into an uncalibrated coulomb counter — which prevents erratic percentage jumps in normal use.

Why the ZUK Edge reports wrong battery percentage after a cell swap

The Z2151 uses a fuel gauge IC that builds its discharge model from the previous cell's coulomb-counting history. When you fit a new BL271, that stored model no longer matches the new cell's actual voltage curve. The gauge reports stale data until it re-learns. One full discharge to shutdown, followed by a complete uninterrupted charge to 100%, resets the calibration and restores accurate reporting.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under modem or display load — even though the OS reports charge remaining. The fuel gauge IC is still using a calibration curve from the degraded original cell, so it underestimates how close the new cell is to its real cutoff voltage. The BMS then trips the protection circuit before the gauge catches up. Run one full discharge cycle without fast charging, and confirm resting cell voltage reads above 3.7V before the next charge — this anchors the new calibration baseline.