Wintec WBT-202 Replacement Battery 3.7V 1000mAh Li-ion

Wintec WBT-202 — 3.7V Li-ion 1000mAh Replacement Battery

This is a 3.7V Li-ion cell rated at 1000mAh (3.7Wh), built to fit the Wintec WBT-202 smartphone. It matches the original cell's dimensions at 53.00 x 33.90 x 5.70mm, so it seats correctly in the battery bay without modification. Use this when the original cell no longer holds a usable charge or fails to power the device through a normal day.

• WBT-202 fit: The WBT-202 uses a compact form-factor cell with a low-current BMS suited to the device's standby-heavy load profile. This replacement matches that connector pinout and BMS handshake so the phone's charge IC recognises the cell on first boot.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the bench. The BMS held cutoff correctly at both ends — no early trip at the high rail, no undervoltage lockout during the discharge taper.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging if available and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before reporting percentage. Skipping this step causes the OS to show inaccurate readings for the first several cycles.

Why the WBT-202 reports wrong battery percentage after a cell swap

The WBT-202 uses a fuel gauge IC that builds its percentage model from the cell's learned discharge curve. When you swap in a fresh cell, that learned curve no longer matches the new cell's actual behaviour. The IC keeps reporting against the old model until it recalibrates. One full discharge down to auto-off, followed by a full uninterrupted charge, resets the coulomb counter and clears the stale curve.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the minimum load threshold under a burst draw — typically screen backlight plus radio activity hitting simultaneously. The fuel gauge still reads 20–30% because it tracks charge capacity, not instantaneous voltage. A cell that hasn't been through a calibration cycle can't sustain the voltage rail under that combined load. Run one full discharge-charge cycle first; if shutdowns continue after that, check that the battery contacts on the phone chassis are clean and making firm contact before replacing the cell again.