About this replacement
Alcatel One Touch Pixi 4 5 — 3.8V Li-ion Replacement Battery (TLI020F7)
This is a 3.8V, 1950mAh lithium-ion cell built to the TLI020F7 specification. It fits the Alcatel One Touch Pixi 4 5, One Touch Pixi 4 (5), One Touch 4 5.0, and the OT-5045 series. The connector layout and BMS communication profile match the original Alcatel hardware.
- OT-5045 series compatibility: These models share the same voltage rail, physical footprint, and BMS handshake protocol. The same TLI020F7 cell works across all variants without modification to contacts or firmware.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the OT-5045 platform. The BMS accepted charge current correctly, maintained voltage above cutoff through screen-on and modem-active load, and triggered protection at the expected lower threshold.
- Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one complete discharge-to-shutdown, then charge to 100% uninterrupted. The fuel gauge IC on the Pixi 4 5 calibrates its coulomb counter against that first full cycle — skipping it causes the percentage readout to drift against the new cell's actual discharge curve.
Why the Pixi 4 5 reports the wrong battery percentage after a cell swap
The Pixi 4 5 uses a fuel gauge IC that stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The IC keeps reporting percentage based on old data until it relearns. One full uninterrupted discharge and charge cycle resets the coulomb counter reference. After that cycle, percentage accuracy returns to normal.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops faster than the fuel gauge expects under combined modem and screen load — the voltage cliff arrives before the displayed percentage reaches zero. On the TLI020F7 cell, this is most common in the first few cycles before the fuel gauge IC has recalibrated. If shutdowns continue after three full cycles, check that the battery connector is fully seated — a partial connection raises internal resistance and steepens the voltage sag under load. Reseat the connector and confirm the cell reads above 3.6V at rest before powering on.