Lenovo Vibe K6 Plus BL270 Replacement Battery 3.85V 4000mAh

Lenovo Vibe K6 Plus / K6 Note — 3.85V Li-Polymer Replacement Battery (BL270)

This is a 3.85V, 4000mAh Li-Polymer replacement battery for the Lenovo Vibe K6 Plus and K6 Note (2016). It carries OEM part number BL270 and slots into the same bay as the original cell. Physical dimensions are 80.30 × 65.90 × 4.20mm — verify clearance before ordering if your unit has any aftermarket back housing.

• K6 Plus and K6 Note compatibility: Both models share the same 3.85V battery bay, BL270 connector pinout, and BMS handshake protocol. The cell and protection circuit are interchangeable across both devices without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Vibe K6 Note unit. The BMS negotiated correctly with the charge IC, held cutoff at 4.35V on full charge, and tripped undervoltage protection cleanly at the low-voltage threshold with no false shutdowns during the test cycles.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one full discharge-to-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state — otherwise percentage readings will drift early on.

Sudden shutdown at 20–30% on the Vibe K6 Plus after a cell swap

A new cell has a slightly different voltage-to-capacity curve than the aged original. The fuel gauge IC on the K6 Plus is still reading the old curve, so it reports 25% remaining at a voltage the new cell actually considers near-floor. Under modem or screen load, the cell voltage dips below the BMS cutoff threshold and the phone shuts off instantly. One full discharge cycle — down to automatic shutdown, then a full uninterrupted charge — forces the coulomb counter to resync to the new cell's actual discharge profile. After that cycle, the reported percentage and real capacity will track correctly.

Phone will not power on after the replacement battery sat in storage

Li-Polymer cells in storage self-discharge slowly. If the cell drops below approximately 2.5V per cell, the BMS enters a lockout state and blocks normal charging to prevent damage to a deeply discharged cell. The phone will show no charge indicator and appear completely dead. Apply a charger and leave it connected for 20–30 minutes without pressing the power button — the charge IC will trickle current into the cell at a low rate until voltage climbs above the BMS re-enable threshold, typically around 3.0V, at which point normal charging resumes.