OnePlus 3T Replacement Battery BLP633 3.85V 3000mAh

OnePlus 3T Series — 3.85V Li-Polymer Replacement Battery (BLP633)

This is a 3.85V, 3000mAh Li-Polymer replacement battery for the OnePlus 3T and 3T Dual SIM (A3010). It fits all regional variants including the Rain edition. Use this when the original BLP633 cell has degraded past the point of holding a useful charge or is causing unexpected shutdowns.

• 3T and A3010 variant coverage: The 3T, 3T Dual SIM, Rain, and A3010 all share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell fits all four without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a 3T unit. The BMS accepted the cell without fault flags, and the charge IC engaged Dash Charge protocol correctly after the first full cycle.
• Fuel gauge recalibration on first use: On first use after installation, disable Dash Charge for one complete discharge-charge cycle. This lets the fuel gauge IC build an accurate discharge curve against the new cell before high-current charging begins on an uncalibrated counter.

Sudden shutdown at 20–30% on the 3T after a cell swap

This is a voltage cliff problem, not a capacity problem. A new cell with a slightly different discharge curve will hit the low-voltage cutoff threshold while the fuel gauge IC still reads 20–30% remaining — because the IC is still calibrated to the old cell. The BMS cuts power to protect the cell before the OS can react. One full discharge-to-zero and slow recharge cycle resets the coulomb counter and eliminates the false-floor shutdown.

OS percentage jumping erratically after battery replacement

The OnePlus 3T uses a coulomb counter in the fuel gauge IC to track remaining capacity. When the original cell is replaced, the IC has no baseline for the new cell's actual capacity and internal resistance. This mismatch causes the percentage reading to jump — sometimes 10–15 points in either direction under load or during charging. Perform one full uninterrupted discharge down to auto-off, then charge to 100% without interruption at standard charge speed to re-anchor the counter.