About this replacement
Philips Xenium V387 — 3.7V Li-Polymer Replacement Battery (AB4400AWMC)
This is a 3.7V, 4700mAh Li-Polymer cell that replaces the original AB4400AWMC battery in the Philips Xenium V387. It fits the V387's battery bay with the same footprint — 92.50 × 62.95 × 5.70mm — and connects via the factory contact strip. Capacity matches the OEM spec exactly as listed in the product data.
- Xenium V387 fit: The V387 uses a fixed connector layout and contact pitch tied to this OEM part number. The AB4400AWMC spec covers both the cell chemistry and the BMS handshake the phone's charge IC expects on first detection.
- Bench tested on actual hardware: We ran this cell through charge-discharge cycles on the V387 platform. The BMS negotiated correctly with the phone's charge controller, and the protection circuit triggered at the expected low-voltage cutoff without false trips.
- Fuel gauge recalibration on first use: On first installation, disable any fast-charge mode and run one complete discharge-to-charge cycle. This lets the phone's fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.
Sudden shutdown at 20–30% on the replacement cell
This is a voltage cliff issue. The Xenium V387's fuel gauge IC was calibrated to the original cell's internal resistance profile. A new cell with a different impedance curve can hit the phone's minimum voltage threshold under modem or screen load while the gauge still reads 20–30%. The phone shuts down to protect the cell, not because capacity is gone. One full discharge cycle — letting the phone run until it powers off on its own, then charging to 100% — allows the coulomb counter to reset and track the new cell accurately. After that cycle, unexpected shutdowns at partial charge should stop.
Phone not powering on after the battery sat in storage
Li-Polymer cells discharged below roughly 2.5V trigger a BMS lockout to prevent cell damage during recovery. If the battery shipped or sat in storage in a deeply discharged state, the V387 may show no sign of life when installed. Connect the phone to a wall charger — not a USB port — and leave it for 15–20 minutes without pressing the power button. The charge IC needs time to push a trickle current past the BMS lockout threshold. Once the cell reaches approximately 3.0V, the BMS releases and the phone will boot or show a charge indicator.