Leagoo C2 Replacement Battery BT-C2 3.7V 900mAh

Leagoo C2 — 3.7V Li-ion Replacement Battery (BT-C2)

This is a 3.7V, 900mAh Li-ion replacement battery for the Leagoo C2 smartphone. It matches the OEM part number BT-C2 and fits the C2 physically at 53.00 × 34.00 × 4.80mm. Swap it in when the original cell no longer holds a charge or shuts the phone down unexpectedly.

• Leagoo C2 fit: The C2 uses a compact single-cell Li-ion pack running at 3.7V nominal. The BT-C2 connector pinout and BMS handshake are matched to the C2's charge IC — no adapter or modification needed.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a C2 unit. The BMS reported charge accepted cleanly, thermal readings stayed within spec, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration after install: On first use, disable fast charging if your C2 supports it, then run one complete discharge-to-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's discharge curve before resuming normal charge rates.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC is still calibrated to the old cell's voltage curve. The new cell hits a steeper voltage drop under modem or screen load, and the phone interprets that as a critically low state before the percentage catches up. It is not a faulty battery — it is a calibration mismatch. Run one full discharge until the phone powers off on its own, then charge uninterrupted to 100% to reset the coulomb counter.

Phone not powering on after the battery sat in storage

If the replacement cell discharged below approximately 2.5V during storage, the BMS enters lockout to prevent cell damage. Plugging in via USB will not always wake it immediately. Connect the original charger and leave it for 15–20 minutes — the charge IC on the C2 delivers a trickle current at around 100mA to bring the cell back above the BMS re-initialisation threshold of roughly 2.8V, after which normal charging resumes.