Philips S226M Compatible Battery 3.7V 1700mAh AB1800BWMT

Philips Xenium S226M — 3.7V Li-ion Replacement Battery (AB1800BWMT)

This is a 3.7V, 1700mAh Li-ion cell replacement for the Philips S226M, CTS226M, and Xenium S226M smartphones. It slots in when the original cell can no longer hold voltage under screen or modem load. Capacity is 1700mAh (6.29Wh), matching the OEM spec for these models.

• S226M, CTS226M, and Xenium S226M compatibility: All three model designations share the same PCB layout, connector pinout, and BMS handshake protocol — AB1800BWMT covers the full variant range without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the S226M platform. The BMS accepted the cell without fault codes, and the charge IC completed a full cycle to 4.2V cutoff with no thermal anomalies.
• Fuel gauge recalibration on first cycle: After installation, disable fast charging and run one complete discharge-charge cycle at standard current. 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 reference.

Sudden shutdown at 20–30% on the Xenium S226M

This is a voltage cliff, not a capacity problem. When the modem transmits or the screen runs at full brightness, current draw spikes and cell voltage drops sharply below the BMS cutoff threshold — even though the fuel gauge still shows charge remaining. An aged or storage-depleted cell has higher internal impedance, which amplifies the voltage sag under load. Running one full discharge-charge cycle after installation lowers the fuel gauge IC's cutoff estimate and lets the cell settle into its actual voltage curve. If shutdowns persist past two full cycles, check that the cell contacts are fully seated and making clean contact at all three terminals.

Phone reports wrong battery percentage after cell swap

The S226M's fuel gauge IC retains a learned discharge curve from the previous cell. When a new cell goes in, the stored curve no longer matches the actual cell chemistry — so the percentage readout drifts or jumps. This is not a fault with the replacement cell; it is the coulomb counter working off stale calibration data. One complete discharge to auto-shutoff followed by a full uninterrupted charge resets the reference points. After that cycle, percentage reporting stabilises to within the normal ±3% tolerance.