TCL 50 Pro Replacement Battery TLP049DA 3.87V 4900mAh

TCL 50 Pro / NXTPAPER 5G — 3.87V Li-Polymer Replacement Battery (TLP049DA)

This is a 3.87V, 4900mAh Li-Polymer replacement battery for the TCL 50 Pro, NXTPAPER 5G, and T702W smartphones. It uses OEM part number TLP049DA and slots directly into the same connector and housing as the factory cell. Capacity figure comes from product data — 18.96Wh total energy.

• 50 Pro, NXTPAPER 5G, and T702W compatibility: All three models share the same 3.87V battery rail, TLP049DA connector footprint, and BMS handshake protocol — one cell covers the whole group without any wiring or adapter changes.
• Bench tested on actual hardware: We cycled this cell through charge, load, and BMS cutoff on T702W hardware. The protection circuit tripped correctly at low-voltage threshold and accepted a full recharge without fault flags on the charge IC.
• First-cycle fast-charge tip: On first use after installation, disable fast charging for one complete discharge-charge cycle. This gives the fuel gauge IC time to recalibrate against the new cell's discharge curve before high-current charging pushes power into an uncalibrated coulomb counter.

Why the TCL 50 Pro reports wrong battery percentage after a cell swap

The fuel gauge IC stores a learned discharge curve from the original cell. Drop in a new cell and that stored curve no longer matches actual cell chemistry or impedance. The OS reads voltage and translates it through the old map, so the percentage displayed can be off by 10–20%. One full discharge down to auto-shutoff followed by a complete charge resets the coulomb counter and forces the IC to relearn the new cell's curve. After that cycle, percentage accuracy returns to normal.

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

This happens when the modem or display draws a current spike the cell cannot sustain at that state of charge — voltage sags below the BMS cutoff threshold even though the gauge still shows 20–30% remaining. It is a calibration gap, not a faulty cell. Run one slow full-cycle charge with fast charging off, let the fuel gauge IC map the actual voltage cliff for this cell, and the shutdowns stop. After calibration, the OS will show a lower percentage before cutoff rather than an abrupt shutdown.