BLP831 Oppo Find X3 Pro Replacement Battery 7.74V 2200mAh

Oppo Find X3 Pro — 7.74V Li-Polymer Replacement Battery (BLP831)

The BLP831 is a 7.74V, 2200mAh Li-Polymer cell that replaces the factory battery in the Oppo Find X3 Pro. It fits the PEEM00, CPH2173, and OPG03 variants — the same hardware sold across different regions under different model codes. Capacity figure is taken directly from the product specification, rated at 17.03Wh.

• Find X3 Pro variant coverage: The PEEM00, CPH2173, and OPG03 share an identical battery bay, connector pinout, and BMS handshake protocol. One cell fits all three without modification.
• Bench tested on actual hardware: We ran the BLP831 through charge and discharge cycles on the CPH2173 board. The BMS accepted the cell on first insertion, and the charge IC held the correct 4.45V per-cell ceiling without intervention.
• Fuel gauge recalibration on first use: Disable VOOC or fast charging for the first full discharge-to-charge cycle after installation. This gives the coulomb counter time to map the new cell's discharge curve before high-current charging pushes load into an uncalibrated gauge.

Sudden shutdown at 20–30% on the Find X3 Pro after a cell swap

This happens because the fuel gauge IC is still running the discharge curve it learned from the old, degraded cell. When the new cell hits a voltage point the old curve didn't predict, the OS reads the drop as a hard zero and forces a shutdown. The phone still has usable charge — the gauge just doesn't know it yet. One complete discharge cycle from 100% to auto-off, followed by a full charge without interruption, resets the coulomb counter against the new cell's actual curve.

USB-PD or VOOC fast charge not accepted on the first cycle

On the first charge after installation, the Find X3 Pro's charge IC may fall back to standard 5V input rather than negotiating VOOC or USB-PD rates. This is the BMS responding cautiously to an uncalibrated cell — it hasn't yet confirmed the internal resistance is within the window that fast charging requires. Let the first cycle complete at standard rate. On the second and subsequent cycles, VOOC negotiation resumes normally once the charge IC has logged one full profile from the new cell.