About this replacement
Xiaomi 14 Pro — 3.87V Li-Polymer Replacement Battery (BP4R)
This 3.87V, 4750mAh Li-Polymer battery replaces the original BP4R cell in the Xiaomi 14 Pro smartphone. It restores full electrical capacity to handsets where the original cell has degraded through repeated charge cycles. Nominal energy output is 18.38Wh at the stock voltage rail.
- Xiaomi 14 Pro fit: The 14 Pro uses a specific connector pinout and BMS handshake tied to Xiaomi's HyperCharge control IC. This BP4R cell matches that connector and communicates correctly with the charge controller — no voltage mismatch, no rejected charge sessions.
- Bench tested on actual hardware: We ran the cell through charge and discharge cycles on the 14 Pro board. The BMS accepted the cell without fault flags, and the coulomb counter tracked state-of-charge without erratic jumps after the first full cycle.
- Fuel gauge recalibration on first install: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before HyperCharge pushes high current into an uncalibrated cell.
Why the Xiaomi 14 Pro reports wrong battery percentage after a cell swap
The 14 Pro uses a coulomb counter that builds its charge model against the original cell's impedance and capacity curve. When a new cell goes in, that model is stale — the IC is predicting state-of-charge against data that no longer matches the physical cell. The result is percentage readings that stick, jump, or refuse to reach 100%. One full slow-charge cycle forces the IC to re-map the curve. After that cycle, readings stabilise.
Sudden shutdown at 20–30% on the replacement cell
This is a voltage cliff, not a capacity problem. Under peak modem or display load, the new cell's voltage drops faster than the fuel gauge predicted — crossing the shutdown threshold before the reported percentage reaches zero. It happens most often before the fuel gauge IC has completed one full recalibration cycle. Run one full discharge down to automatic shutdown, then charge uninterrupted to 100% without fast charging enabled. After that cycle, the IC's low-voltage cutoff prediction aligns with the actual cell curve.