About this replacement
Wiko Fever / Fever 4G — 3.8V Li-Polymer Replacement Battery (TLP15J15)
This 3.8V, 3000mAh (11.4Wh) lithium-polymer cell replaces the original battery in the Wiko Fever and Fever 4G smartphones. It fits OEM part numbers TLP15J15, TLP15L27, TLP15J30, and TLP16F14. Use this when your Fever no longer holds a charge, shuts down unexpectedly, or fails to power on.
- Fever and Fever 4G fit: Both variants share the same battery bay dimensions and connector pinout. The 75.75 × 60.70 × 4.20mm cell slots into either chassis without modification, and the BMS communicates over the same three-pin thermistor line used by the OEM cell.
- Bench tested on actual hardware: We cycled this cell through a full discharge-charge sequence on the Fever platform. The BMS accepted the charge handshake without fault codes, and the protection circuit engaged at the correct cutoff thresholds on both ends of the voltage range.
- Fuel gauge recalibration after swap: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before reporting accurate percentages — skipping this step is the main cause of erratic readings post-swap.
Sudden shutdown at 20–30% on the Wiko Fever after a cell replacement
This is a voltage-cliff issue, not a capacity defect. Under modem transmission or screen-at-full-brightness load, a fresh cell can sag below the SoC threshold the fuel gauge expects at that reported percentage. The phone interprets the voltage drop as an empty cell and cuts power. One full slow-charge cycle lets the coulomb counter re-anchor its low-voltage floor, which moves that cliff down to where it belongs — typically below 5%.
USB charging not accepted on the first cycle after fitting the replacement cell
The Wiko Fever's charge IC negotiates current draw with the BMS before ramping voltage. A replacement cell that has rested in storage at a low state of charge can present a high impedance on the first contact, causing the charge IC to abort the session and show no charging indicator. Connect the phone to a standard 5V/1A charger — not a fast charger — for 10–15 minutes to bring the cell above 3.0V per cell. Once the BMS releases its lockout, normal charging resumes and fast charge can be re-enabled.