About this replacement
Alcatel One Touch Pixi 4 6" Series — 3.85V Li-ion Replacement Battery (TLi025A1)
This is a 3.85V, 2400mAh Li-ion replacement battery for the Alcatel One Touch Pixi 4 6" and Pixi 4 6.0 LTE smartphones. It covers OT-9001A and OT-9001X variants. The TLi025A1 part number matches the original cell footprint and connector at 70.50 × 62.10 × 4.20mm.
- OT-9001A and OT-9001X coverage: Both variants run the same 3.85V battery rail, use the same physical connector, and accept the same BMS handshake — one cell fits all four listed models without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the OT-9001 platform. The BMS accepted the charge curve without error flags, and the protection circuit triggered correctly at the low-voltage cutoff threshold.
- Fuel gauge recalibration on first use: Disable fast charging for the first complete discharge-charge cycle after installation. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins on an uncalibrated cell — skipping this step often causes erratic percentage readings for the first several days.
Sudden shutdown at 20–30% on the Pixi 4 6"
This happens when an aged cell can no longer hold its voltage under the combined load of the modem radio, display, and active apps. Even though the fuel gauge reports 20–30% remaining, the cell voltage collapses below the BMS cutoff threshold the moment load spikes. A new cell restores the voltage headroom that keeps the device running through those load bursts. After fitting the replacement, run one full discharge to 0% and charge to 100% uninterrupted so the coulomb counter resets to the new cell's actual capacity.
Phone reports wrong battery percentage after cell swap
The Pixi 4 6" uses a fuel gauge IC that builds its capacity model from the previous cell's discharge history. After a replacement, that stored curve no longer matches the new cell and the reported percentage drifts — sometimes reading 100% at 3.95V or dropping 15% in seconds. One full discharge-charge cycle forces the IC to relearn the discharge profile against the new cell. After that single calibration cycle, percentage accuracy returns to normal and erratic jumps stop.