Wiko GOA Replacement Battery 3.7V 1200mAh Li-ion

Wiko GOA / Sunny Series — 3.7V Li-ion Replacement Battery (GOA,2502)

This is a 3.7V, 1200mAh Li-ion cell replacing the original battery in Wiko GOA, Sunny, 9662, and Tramonto smartphones. It matches the OEM voltage and physical footprint at 52.23 × 50.93 × 4.50mm. Fit the connector tab correctly and the phone will recognise the cell immediately.

• GOA / Sunny platform compatibility: These four models share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail. The BMS on each handshakes to the same charge IC, so one cell covers all four without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a GOA unit. The BMS accepted the charge profile without fault codes, and the protection circuit triggered correctly at the low-voltage cutoff threshold.
• 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 cell — preventing erratic percentage readings from the first day.

Sudden shutdown at 20–30% on the Wiko GOA after a cell swap

The GOA's fuel gauge IC retains the discharge curve from the old degraded cell after a swap. When the new cell's open-circuit voltage drops into the 3.6–3.7V range under modem or screen load, the IC incorrectly maps this to a near-empty state and triggers a protective shutdown. The fix is a full uninterrupted discharge to automatic power-off, followed by a full charge without interruption. After that single calibration cycle, the IC rewrites its reference curve and the shutdowns stop.

Phone reports wrong battery percentage after replacement cell installed

The coulomb counter inside the GOA's charge IC was calibrated against the old cell's internal resistance and capacity fade profile. A fresh 1200mAh cell has lower impedance, so the counter over- or under-reports state of charge for the first few cycles. You will see the percentage jump or stall at fixed points. Run one full discharge to zero — let the phone power off on its own — then charge uninterrupted to 100%. The fuel gauge IC re-anchors its endpoints and percentage tracking stabilises from the next cycle onward.