Alcatel TLi015A1 Replacement Battery 3.7V 1650mAh

Alcatel OT-975 / One Touch 975 Series — 3.7V Li-ion Replacement Battery (TLi015A1)

This is a 3.7V, 1650mAh Li-ion replacement battery for the Alcatel OT-975, OT-975N, One Touch 975, and One Touch 975N smartphones. It carries OEM part number TLi015A1 and matches the original cell's physical dimensions at 51.83 x 50.78 x 5.41mm. Swap it in when the original cell no longer holds a charge or causes unexpected shutdowns.

• OT-975 and One Touch 975 compatibility: The OT-975 and its 975N variant share the same battery bay dimensions, connector pinout, and BMS handshake — all four models use TLi015A1 interchangeably without modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the OT-975 platform. The BMS accepted charge immediately, voltage held steady through screen and modem load, and protection circuits tripped correctly at both overvoltage and undervoltage thresholds.
• Fuel gauge recalibration on first use: After installing this cell, run one complete discharge-charge cycle with fast charging disabled. This gives the phone's fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes into an uncalibrated state — which is the direct cause of erratic percentage jumps after a cell swap.

Sudden shutdown at 20–30% on the OT-975 after a cell swap

This is a voltage-cliff issue, not a capacity problem. When the modem fires during a call or data burst, current draw spikes sharply — if the cell voltage sags below the BMS cutoff threshold under that load, the phone cuts out even though the fuel gauge still reads 20–30%. The fuel gauge IC was calibrated to the old cell's internal resistance curve, so it misreads how much charge is actually left. One full discharge-charge cycle without fast charging lets the coulomb counter reset against the new cell and the shutdowns stop. After that cycle, charge normally to 4.2V.

OT-975 showing wrong battery percentage after replacement

The phone's fuel gauge IC stores a learned model of the original cell's discharge curve. A new cell has different internal resistance, so the IC reads voltage against the wrong model and reports an inaccurate percentage — often jumping several points at once. This is not a fault with the replacement cell. Discharge the phone to automatic shutdown, then charge uninterrupted to 100% with the screen off. After one full cycle the IC recalibrates, and percentage reporting stabilises.