Alcatel 5005R Replacement Battery TLi021G1 3.8V 2000mAh

Alcatel 5005R / Insight — 3.8V Li-ion Replacement Battery (TLi021G1)

This is a 3.8V, 2000mAh (7.6Wh) Li-ion cell for the Alcatel 5005R and Insight smartphone. It replaces OEM part TLi021G1 and fits the same connector and footprint as the factory cell. Swap it in when the original no longer holds a working charge through a normal day.

• 5005R and Insight compatibility: Both the 5005R and Insight share the same battery bay dimensions, connector pinout, and BMS handshake protocol — that is why one cell covers both model names. The TLi021G1 part number is the key identifier, not the model name on the box.
• Bench tested on actual hardware: We cycled this cell on a 5005R unit and confirmed the BMS accepted the cell without fault codes, charge termination completed at the correct cutoff voltage, and the fuel gauge IC registered a full 100% state of charge at end of cycle.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-to-charge cycle before normal use. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the TLi021G1 replacement cell

This is a voltage cliff issue. A degraded or new uncalibrated cell can drop below the BMS cutoff threshold — typically around 3.2V under load — while the fuel gauge still reads 20–30% remaining. The phone shuts off not because it is empty, but because the cell voltage collapsed under the current draw of the modem or screen. One full calibration cycle usually closes the gap between the fuel gauge reading and actual cell voltage under load.

Phone reads incorrect battery percentage after cell swap

The fuel gauge IC on the 5005R uses a stored discharge curve to estimate state of charge — that curve was built around the original cell's impedance profile. A new cell has a different impedance, so the IC reads high or low until it recalibrates. Charge to 100%, let the phone discharge naturally to below 5% without interruption, then charge back to 100% uninterrupted. After that single full cycle, percentage reporting typically stabilises.