BlackView BV5500 Compatible Battery 3.85V 4000mAh 416078PH

BlackView BV5500 — 3.85V Li-Polymer Replacement Battery (416078PH)

This is a 3.85V, 4000mAh Li-Polymer battery built to fit the BlackView BV5500 rugged smartphone. It replaces OEM part number 416078PH directly. Swap it in when the original cell no longer holds charge through a normal day.

• BV5500 cell fitment: The BV5500 uses a fixed connector and a BMS that checks cell voltage and internal resistance at boot. This replacement matches the original voltage rail and connector pinout, so the phone's charge IC accepts the cell without firmware complaints.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the BV5500 board. The BMS balanced correctly, charge termination triggered at full capacity, and no over-temperature flags appeared during the fast-charge phase.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging for the first complete discharge-charge cycle. The BV5500's fuel gauge IC is calibrated to the old cell's discharge curve. One full slow cycle lets the coulomb counter reset against the new cell before high-current charging begins.

Why the BV5500 reports wrong battery percentage after a cell swap

The BV5500 uses a coulomb counter in the fuel gauge IC to track state of charge. That counter is calibrated to the internal resistance and discharge curve of the original cell. A new cell has different impedance, so the learned curve no longer matches reality. The phone reads percentage from a map built on old data. One full discharge to auto-shutdown followed by a complete charge cycle forces the IC to relearn the curve against the new cell.

Sudden shutdown at 20–30% on the BV5500 after replacement

This happens when the fuel gauge IC fires a shutdown before the cell is actually depleted. The BMS trips because the reported state of charge still follows the old cell's voltage cliff model. Under modem or screen load, voltage sags enough to trigger the protection threshold even though real capacity remains. Run one uninterrupted discharge-charge cycle without interruption — let the phone shut itself off naturally at low voltage, then charge to 100% — to push the gauge IC to reset its threshold map to 3.0V per cell floor.