Auro M101 Replacement Battery BP-75LI 3.7V 1050mAh

Auro M101 / Comfort 10xx Series — 3.7V Li-ion Replacement Battery (BP-75LI)

This 3.7V 1050mAh Li-ion battery replaces the BP-75LI cell in the Auro M101, M401, and Comfort 10xx smartphones including the Comfort 1010. It is a direct swap for the original cell when capacity fade or a failed battery leaves the phone unable to hold a usable charge. Voltage and capacity match the original OEM specification exactly.

• M101, M401, and Comfort 10xx compatibility: These models share the same 3.7V single-cell architecture, BP-75LI footprint, and connector pinout. The BMS handshake and charge termination voltage are identical across the range, so one cell covers all listed variants without modification.
• Bench tested on actual hardware: We ran charge and discharge cycles on the M101 and Comfort 1010. The BMS accepted charge termination at 4.2V, triggered low-voltage cutoff cleanly at 3.0V, and showed no thermal anomalies across three full cycles.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging is applied to an uncalibrated cell.

Sudden shutdown at 20–30% on a freshly installed cell

A new cell with an uncalibrated fuel gauge IC will hit a voltage cliff before the percentage display reaches zero. Under load from the modem or screen, the cell voltage drops faster than the IC predicts, triggering a hard shutdown while the OS still shows charge remaining. This is not a fault with the cell — it is the fuel gauge reading from the old cell's discharge curve. One full discharge to automatic cutoff followed by a full charge resolves the mismatch. After that cycle the reported percentage should track the actual state of charge accurately.

Phone not powering on after the battery sat discharged in storage

Li-ion cells that have self-discharged below approximately 2.5V trigger a BMS lockout to prevent damage from charging a deeply depleted cell. The phone will show no response — no charging indicator, no boot screen. Connect to a wall charger rather than a USB port and leave it for 20–30 minutes without pressing any buttons. Most BMS circuits on this cell platform resume trickle charge automatically once the charger is detected, and the phone will begin normal boot once the cell recovers above 3.0V.