Lenovo K3 BL242 Replacement Battery 3.7V 1900mAh

Lenovo K3 / A6000 Series — 3.7V Li-ion Replacement Battery (BL242)

This is a 3.7V, 1900mAh Li-ion replacement battery for the Lenovo K3, K30-T, A6000, and A6000 Dual SIM smartphones. It carries OEM part number BL242 and slots directly into the same battery bay as the original cell. Use it when the original battery no longer holds a charge or has swollen and needs replacing.

• K3 / A6000 platform fit: The K30-T, A6000, and A6000 Dual SIM all share the same battery bay dimensions and BL242 connector pinout. One cell covers all four models because the voltage rail and BMS handshake requirements are identical across that device family.
• Bench tested on actual hardware: We cycled this cell on a K30-T unit and confirmed the BMS accepted the cell without a voltage-mismatch error. Charge acceptance ran clean from 3.0V through the 4.2V cutoff with no mid-cycle interruptions.
• Fuel gauge recalibration on first install: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated counter — preventing erratic percentage readings from day one.

Sudden shutdown at 20–30% on the BL242 replacement cell

This is a voltage-cliff problem, not a capacity problem. Under peak modem or screen load, the cell voltage drops faster than the fuel gauge IC predicts, and the phone shuts off before the displayed percentage reaches zero. The root cause is the fuel gauge IC still running a lookup table calibrated to the old, degraded cell. One full discharge-charge cycle at standard rate rewrites that table to match the new cell's actual discharge curve. After that cycle, the percentage reading and the shutdown threshold align correctly.

Phone won't power on after the BL242 sat in storage uncharged

Li-ion cells self-discharge over time. If the cell drops below approximately 2.5V, the BMS enters a lockout state and blocks normal charge current to prevent damage to a deeply depleted cell. The phone will show no charging indicator and won't respond to the power button. Connect to a wall charger — not a PC USB port — and leave it for 15 to 30 minutes without pressing anything. A wall charger delivers enough current to push the BMS past its re-initialisation threshold; once the cell reaches around 3.0V, normal charging resumes and the phone will boot.