Alcatel One Touch Pixi 4 TLi015M1 Replacement Battery 3.8V 1200mAh

Alcatel One Touch Pixi 4 4.0 / OT-4034 Series — 3.8V Li-ion Replacement Battery (TLi015M1)

This is a 3.8V, 1200mAh Li-ion replacement battery for the Alcatel One Touch Pixi 4 4.0 smartphone. It fits the OT-4034, OT-4034D, and OT-4034X variants. OEM part numbers TLi015M1, TLi015M7, and TLi015MA all cross to this cell.

• OT-4034 series compatibility: The OT-4034, OT-4034D, and OT-4034X share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell fits all three without modification.
• Bench tested on actual hardware: We ran this cell through a full charge and discharge cycle on the OT-4034 platform. The BMS accepted the new cell without triggering a reject flag, and charge termination fired correctly at the 4.35V ceiling.
• Fuel gauge recalibration on first use: Disable fast charging for the first complete discharge-charge cycle after installation. The Pixi 4's fuel gauge IC is calibrated to the old cell's discharge curve. Running one uninterrupted cycle at standard current lets the coulomb counter reset its reference points before high-current charging begins.

Why the Pixi 4 reports wrong battery percentage after a cell swap

The OT-4034 uses a fuel gauge IC that tracks charge state against a stored discharge curve from the original cell. When you install a new cell, that curve no longer matches the actual voltage-to-capacity relationship of the replacement. The gauge reads capacity from a reference that is now wrong. One full discharge down to auto-shutdown, followed by an uninterrupted charge to 100%, resets the coulomb counter and brings percentage reporting back into line.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under load — the modem radio or display pulls current and the cell cannot sustain voltage above the BMS cutoff threshold, even though the gauge still shows charge remaining. It is a voltage-cliff issue, not a capacity defect. A degraded original cell masks this because its discharge curve has flattened over time. After one full recalibration cycle, the fuel gauge IC maps the new cell's actual cliff point and shuts down at the correct percentage — typically below 5V open-circuit drop triggers a protect cut at 3.0V per cell.