About this replacement
Oppo Realme 10 5G — 3.87V Li-Polymer Replacement Battery (BLP957)
This is a 3.87V, 4900mAh Li-Polymer replacement battery for the Realme 10 5G (RMX3630). It replaces OEM part BLP957 and restores power to the phone's processor, display, modem, and all onboard functions. Install it when the original cell no longer holds a usable charge or shuts down unexpectedly under load.
- Realme 10 5G and RMX3630 fitment: Both model references share the same physical cell format, connector pinout, and BMS handshake protocol — one battery covers both without modification.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a Realme 10 5G unit. The BMS communicated correctly with the charge IC, accepted charging current without rejection, and reported state-of-charge data to the OS throughout.
- First-cycle fuel gauge calibration: 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 high-current charging applies to an uncalibrated state-of-charge register.
Sudden shutdown at 20–30% on the replacement cell
A new Li-Polymer cell has a steeper voltage drop at its lower capacity range than a partially degraded original cell. When the modem or display pulls peak current in that range, the cell voltage sags below the BMS cutoff threshold — triggering a hard shutdown even though the OS still reports charge remaining. This is a fuel gauge calibration gap, not a faulty battery. Run one full discharge to auto-off, then charge uninterrupted to 100% — the coulomb counter resets against the actual cell curve and the shutdowns stop.
USB-PD or proprietary fast charge not working after replacement
After a cell swap, the charge IC on the Realme 10 5G may default to trickle or standard 5V charging on the first cycle because the BMS handshake resets to a safe initial state. The fast-charge protocol negotiation between the charger and the phone's PMIC requires a completed charge cycle before it unlocks full current. Plug into the original Oppo/Realme fast charger, let the phone charge to 100% without interruption, then disconnect and reconnect — fast charging typically re-enables on the second connection.