About this replacement
Philips Xenium W6618 — 3.8V Li-Polymer Replacement Battery (AB5300AWMC)
This is a 3.8V, 5000mAh Li-Polymer replacement battery for the Philips Xenium W6618 smartphone. It fits directly into the W6618 and matches the OEM connector and BMS handshake for that model. Capacity listed here comes from product data — 5000mAh, 19Wh.
- Xenium W6618 platform fit: The W6618 uses a specific connector pinout and BMS communication protocol tied to the AB5300AWMC part number. This cell matches that spec — voltage rail, connector orientation, and charge termination signal all align with the OEM BMS on this model.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the W6618 board. The BMS accepted the cell, charge termination triggered correctly at 4.35V, and protection circuits tripped as expected under over-current simulation.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. The W6618 fuel gauge IC calibrates its coulomb counter against the cell's actual discharge curve — skipping this step with fast charging active pushes high current into an uncalibrated cell and causes the percentage readout to drift immediately.
Sudden shutdown at 20–30% on the Xenium W6618
This is a voltage cliff issue, not a capacity issue. When the modem transmits or the screen runs at full brightness, instantaneous current draw spikes. If the cell's internal impedance is elevated — common in aged or deeply discharged cells — voltage drops sharply under that load, hitting the BMS cutoff threshold even though the fuel gauge still reads 20–30%. The fix is a full recalibration cycle: discharge the phone to automatic shutdown, charge to 100% without interruption, and let the coulomb counter reset its baseline. If shutdowns continue after two full cycles, the cell's impedance is too high and replacement is the correct step.
Phone not powering on after the replacement battery sat in storage
Li-Polymer cells self-discharge in storage, and if voltage drops below 2.5V per cell the BMS enters lockout mode to prevent damage — the phone will show nothing when you press power. Connect the W6618 to a charger and leave it for 20–30 minutes before attempting to power on. The charge IC needs to trickle current into the cell to bring it above the BMS re-enable threshold, which on this platform sits around 2.7–3.0V. Once the charging LED or indicator activates, the BMS has cleared lockout and normal boot will proceed.