Nokia C3 2020 SP330 Replacement Battery 3.85V 2950mAh

Nokia C3 2020 — 3.85V Li-ion Replacement Battery (SP330)

This is a 3.85V, 2950mAh Li-ion cell built to the SP330 specification for the Nokia C3 2020 smartphone. It replaces the original battery when capacity has faded and the phone can no longer hold a charge through normal daily use. Voltage, physical dimensions (84.00 × 63.90 × 4.00mm), and connector orientation match the original fitment.

• Nokia C3 2020 fitment: The C3 2020 uses a single-cell 3.85V architecture with a fixed BMS handshake tied to the SP330 part spec. This cell carries the correct protection circuit to communicate charge state back to the phone's fuel gauge IC without triggering fault flags.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on the C3 2020 platform. The BMS accepted charge at both standard and fast-charge rates, and the protection circuit tripped correctly at the low-voltage cutoff threshold — no false disconnects during the draw cycle.
• First-cycle calibration tip: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before fast-charge current is applied to an uncalibrated cell.

Why the C3 2020 reports wrong battery percentage after a cell swap

The C3 2020 uses a coulomb-counting fuel gauge IC that learns the discharge curve of the installed cell over time. When a new cell goes in, the IC is still calibrated to the old cell's impedance profile, so percentage readings drift — often showing 100% too quickly or dropping suddenly in the 30–40% range. The fix is one full uninterrupted discharge to below 5% followed by a full charge to 100% with the screen off. After that cycle, the IC resets its reference points against the actual new cell curve and percentage accuracy stabilises.

Sudden shutdown at 20–30% remaining on the new cell

This happens when the fuel gauge IC hasn't yet recalibrated and the phone hits the hardware low-voltage cutoff before the reported percentage catches up. Under modem or screen load, the new cell's voltage drops faster than the old profile predicts, and the BMS cuts power to protect the cell at roughly 3.4–3.5V even though the display still shows charge remaining. Run one full discharge-charge cycle without interruption to resync the fuel gauge. After calibration, the reported percentage and the actual cell voltage align, and the shutdowns stop.