TLP038C7 Alcatel 5V Compatible Battery 3.85V 3900mAh

Alcatel 5V / OT-5060D / OT-5060A — 3.85V Li-Polymer Replacement Battery (TLP038C7)

This is a 3900mAh, 3.85V lithium-polymer cell that replaces the TLP038C7 battery in the Alcatel 5V, OT-5060D, and OT-5060A smartphones. It fits phones that have stopped holding charge, shut down unexpectedly, or have a swollen original cell. Capacity matches the OEM spec at 15.02Wh.

• 5V / OT-5060D / OT-5060A platform fit: All three model numbers share the same PCB layout, connector pinout, and BMS handshake protocol. The TLP038C7 cell communicates directly with the phone's fuel gauge IC — a mismatched cell will trigger charge cutoff or incorrect reporting from day one.
• Bench tested on actual hardware: We cycled this cell through charge, discharge, and a full modem-load draw test. The BMS held cutoff voltage correctly at both ends, and the charge IC accepted the cell without throwing an error state.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.

Sudden shutdown at 20–30% on the Alcatel 5V after a cell swap

This happens because the fuel gauge IC is still using the discharge curve from the old, degraded cell. When the new cell reaches a voltage point the IC hasn't seen before, it misreads state-of-charge and triggers a shutdown at what looks like 20–30% remaining. The phone isn't actually at that charge level — the coulomb counter is out of sync with the new cell. One full discharge to auto-off followed by an uninterrupted charge to 100% resets the calibration.

USB fast charge not activating after installing the TLP038C7

On the first cycle after a cell swap, the charge IC sometimes refuses to negotiate the fast-charge protocol until it has completed at least one standard charge cycle. This is a BMS protection behaviour — the controller won't accept elevated current into a cell it hasn't profiled yet. Charge once at standard speed using the original cable and wall adapter. Fast charging typically resumes normally from the second cycle onward.