Philips AB1050DWM Xenium X810 Compatible Battery 3.7V 900mAh

Philips Xenium X810 / X650 / X510 / X605 — 3.7V Li-ion Replacement Battery (AB1050DWM)

This is a 3.7V, 900mAh Li-ion replacement battery for the Philips Xenium X810, X650, X510, and X605 feature phones. It uses OEM part number AB1050DWM and matches the original cell format at 45.18 × 41.25 × 5.42mm. Swap it in when the original cell no longer holds enough charge for a full day of use.

• Xenium X810 / X650 / X510 / X605 compatibility: These four Xenium models share the same battery bay dimensions, connector pinout, and 3.7V single-cell architecture — one replacement cell fits all four without modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Xenium handset, confirmed the BMS accepted the charge IC handshake, and verified the protection circuit tripped correctly at undervoltage rather than allowing a deep-discharge lockout.
• Fuel gauge recalibration on first use: After fitting this cell, disable any fast-charge mode for the first complete discharge-charge cycle. The Xenium's fuel gauge IC needs one full cycle against the new cell's discharge curve before it can report percentage accurately — skipping this step causes erratic percentage readings in the first few days.

Sudden shutdown at 20–30% on the Xenium after a cell swap

This happens because the fuel gauge IC is still calibrated to the discharge curve of the old, degraded cell. When the new cell hits a voltage point the IC associates with a higher state of charge, the system still reads it as 20–30% — but the actual cell voltage is already near the protection cutoff. Under screen or call load, voltage sags just enough to trip the BMS at what appears to be 25% remaining. One full discharge-to-cutoff and charge-to-100% cycle resets the coulomb counter reference. After that cycle, the percentage readout tracks correctly down to actual cutoff near 3.0V per cell.

Phone warm near the battery compartment on the first few charges

A freshly manufactured Li-ion cell has slightly higher internal impedance than a broken-in cell. During the first two or three charges, the charge IC pushes current into a cell with more resistance than it expects, and that converts some energy to heat. This is normal for the first three cycles and settles once the cell's impedance drops into its working range. If warmth persists beyond five full charge cycles or the phone becomes hot to the touch, check that the battery cover is seated flat — a lifted cover traps heat against the back panel and compounds the issue.