Wiko Rakuten Mini TJL2004 Replacement Battery 3.85V 1150mAh

Wiko Rakuten Mini / C330 — 3.85V Li-Polymer Replacement Battery (TJL2004)

This is a 3.85V, 1150mAh Li-Polymer cell for the Wiko Rakuten Mini and C330 smartphones. It replaces OEM part number TJL2004, which sits inside the compact body of the Rakuten Mini. If your phone shuts down early, charges slowly, or drains faster than it used to, the original cell has degraded and this swap restores the hardware to spec.

• Rakuten Mini and C330 fitment: Both models share the same compact chassis, the same 3.85V power rail, and the same connector pinout. The BMS handshake and charge IC thresholds are identical across the two, so one cell covers both without any modification.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the Rakuten Mini platform. The BMS accepted charge immediately, charge termination triggered correctly at 4.35V, and the protection circuit tripped cleanly at low-voltage cutoff without latching the BMS into lockout.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This allows the fuel gauge IC to map the new cell's discharge curve before fast-charge current is applied to an uncalibrated state.

Why the Rakuten Mini reports wrong battery percentage after a cell swap

The Rakuten Mini uses a fuel gauge IC that tracks capacity through a coulomb counter calibrated to the original cell's discharge curve. When you install a new cell, the stored curve no longer matches the actual voltage-to-capacity relationship of the fresh battery. The IC makes incorrect estimates — typically showing more charge than exists at mid-range, then dropping suddenly. One full discharge down to automatic shutdown, followed by an uninterrupted charge to 100%, resets the counter reference point and brings percentage readings back into alignment.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem radio or screen draws a current spike the cell cannot sustain without the terminal voltage collapsing below the BMS cutoff threshold. The fuel gauge still reports 20–30% remaining, but the cell's internal resistance under load causes an instantaneous voltage drop that triggers shutdown. It is most common in the first few cycles before the cell conditions. If it persists past three full cycles, verify the installed cell dimensions match 45.90 × 40.10 × 4.55mm — a slight mismatch can cause poor contact and elevated resistance at the terminal.