Philips E166 Replacement Battery 3.7V 950mAh AB1000BWMT

Philips E166 / Xenium Series — 3.7V Li-ion Replacement Battery (AB1000BWMT)

This is a 3.7V, 950mAh Li-ion cell built to replace the original AB1000BWMT battery in the Philips E166 and related handsets. It fits the E166, E220, CTE166, and Xenium E166. Swap it in when the original cell no longer holds charge through a standard day of calls and messages.

• E166 / Xenium platform fit: The E166, E220, CTE166, and Xenium E166 all share the same battery bay dimensions, 3.7V supply rail, and AB1000BWMT connector pinout. One cell covers the full group.
• Bench tested on actual hardware: We cycled this cell on an E166 unit and confirmed the BMS handshake completed on first insertion — charge IC accepted the cell without triggering a fault flag or refusing to enter CC phase.
• Fuel gauge recalibration on first use: On first use after fitting this cell, disable any fast-charge mode and run one full discharge-charge cycle at standard rate. This lets the fuel gauge IC map its coulomb counter against the new cell's discharge curve before high-current charging begins on an uncalibrated profile.

Why the E166 reports wrong battery percentage after a cell swap

The E166 uses a fuel gauge IC that builds its percentage model from accumulated charge and discharge data on the old cell. When a new cell goes in, that learned curve no longer matches reality. The IC keeps estimating from stale data until it completes at least one full discharge-to-charge cycle on the replacement. Until recalibration runs, you may see jumps or a reading that stalls at a fixed percentage. Run the phone down to auto-shutdown once, then charge uninterrupted to 100% — that single cycle resets the coulomb counter baseline.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under load — typically during a call or when the screen backlight peaks — even though the displayed percentage suggests charge remains. The fuel gauge IC triggers a protection shutdown once the cell hits roughly 3.0V under that instantaneous draw, which can occur well before 0% is shown. It is a voltage-cliff symptom, not a faulty cell. Recalibrate the gauge with one full cycle and verify the shutdown moves closer to 5% before replacing the cell a second time.