About this replacement
OnePlus 8 5G — 3.85V Li-Polymer Replacement Battery (BLP761)
This is a 3.85V, 4200mAh Li-Polymer replacement battery for the OnePlus 8 5G smartphone. It fits models N20190, IN2010, and IN2017. Swap it when the original cell can no longer hold a charge across a full day of use.
- N20190 / IN2010 / IN2017 compatibility: These model numbers share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The BLP761 cell fits all three without hardware modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on an IN2010 unit. The BMS accepted the cell on first connection, charge current ramped correctly, and the protection circuit tripped at the expected low-voltage threshold.
- Fuel gauge recalibration on first use: After installation, disable Warp Charge and run one full discharge-to-charge cycle on standard charging. This lets the coulomb counter recalibrate against the new cell's discharge curve before high-current charging begins on an uncalibrated cell.
Why the OnePlus 8 5G reports wrong battery percentage after a cell swap
The fuel gauge IC on the OnePlus 8 5G stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The OS reads a voltage point from the old curve and reports the wrong percentage. One full discharge below 5% followed by a complete charge to 100% on standard charging resets the coulomb counter and forces the gauge IC to build a new curve from scratch.
Sudden shutdown at 20–30% charge remaining on the new cell
This is a voltage cliff, not a capacity fault. Under high loads — 5G modem activity, screen at full brightness, or simultaneous background sync — the new cell's voltage drops faster than the fuel gauge predicts. The system voltage falls below the BMS cutoff threshold before the display percentage reaches zero. The fix is the same recalibration cycle: one full discharge to near-empty followed by a full charge. Check that the percentage holds stable under load at or above 3.6V before calling the cell defective.