About this replacement
BlackView BV9000 Pro — 3.8V Li-Polymer Replacement Battery (U536174P)
This is a 3.8V, 3900mAh Li-Polymer cell built to fit the BlackView BV9000 Pro rugged smartphone. It replaces part number U536174P and restores power to the processor, display, and cellular radio. Capacity figure is 14.82Wh as rated on this cell.
- BV9000 Pro fitment: The BV9000 Pro uses a specific connector orientation and BMS handshake tied to the U536174P cell footprint. This replacement matches that footprint — 75.50 x 59.80 x 5.16mm — so the BMS communicates correctly with the phone's charge IC without triggering a battery authentication fault.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the BV9000 Pro platform. The BMS accepted the cell without lockout, the charge IC stepped through its CC/CV stages cleanly, and the coulomb counter initialised without throwing a calibration error on the first cycle.
- Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state — which can cause erratic percentage readings from the start.
Sudden shutdown at 20–30% on the BV9000 Pro after a cell swap
This happens when the fuel gauge IC is still calibrated to the old cell's discharge curve. The phone's OS reads an estimated 25% remaining, but the new cell's actual voltage under modem or screen load drops below the shutdown threshold faster than the old curve predicted. The phone cuts out to protect the SoC — not because the cell is faulty. One full discharge-charge cycle at standard rate gives the coulomb counter enough data to rebuild its model against the new cell. After that cycle, shutdowns in this range stop.
Fast charging not working on the first cycle after replacement
On first boot with a new cell, the BV9000 Pro's charge IC may reject the USB fast-charge handshake if the BMS has not yet confirmed cell state to the charge controller. The phone defaults to standard 5V charging as a protective fallback — this is normal behaviour, not a defect. Complete one full standard charge cycle first. On the second charge, the BMS passes cell status to the charge IC and fast charging re-engages at full current.