Alcatel OT-8050D Replacement Battery TLp025DC 3.8V 2500mAh

Alcatel One Touch Pixi 4 6.0 / OT-8050D — 3.8V Li-Polymer Replacement Battery (TLp025DC)

This 3.8V, 2500mAh (9.5Wh) lithium-polymer cell replaces the original TLp025DC and TLp025D2 batteries in the Alcatel OT-8050D and One Touch Pixi 4 6.0 series. It fits the standard 75.48 × 69.55 × 3.10mm battery bay and connects to the same three-contact board as the original. Capacity figures are taken from the product data, not estimated from third-party sources.

• Pixi 4 6.0 and OT-8050D platform fit: These models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell works across the full compatibility group without modification.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on the OT-8050D. The BMS accepted the cell without triggering a protection cutoff, and the charge IC held a steady 4.35V termination voltage at end of charge.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes load into an uncalibrated cell.

Sudden shutdown at 20–30% on the OT-8050D after a cell swap

The OT-8050D's fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, the IC keeps using that old curve. Near the bottom of the charge window, the new cell's actual voltage drops below what the modem and display can sustain under load — causing an abrupt cutoff even though the OS still shows charge remaining. One complete discharge cycle lets the coulomb counter relearn the new cell's voltage curve and move the shutdown point to the correct floor, typically around 3.4–3.5V under load.

Phone reports wrong battery percentage after replacement

The Android fuel gauge IC on this platform calibrates percentage against a stored cell model — not a live voltage reading. After fitting a new cell, the IC is still referencing the degraded curve of the old battery, so displayed percentage jumps or reads high early and drops fast near the end. Charge the phone to 100% without interruption, then let it discharge fully to auto-shutdown, then charge back to 100% in one uninterrupted session. After that single cycle, the coulomb counter resets its baseline and percentage tracking stabilises.