About this replacement
Philips Xenium S326 / CTS326 — 3.8V Li-ion Replacement Battery (AB3000IWMC)
This is a 3.8V, 2800mAh Li-ion battery for the Philips Xenium S326 and CTS326 smartphones. It replaces OEM part AB3000IWMC and fits the original battery bay with the same connector and cell dimensions. Voltage and capacity figures match the factory spec exactly.
- Xenium S326 and CTS326 compatibility: Both models share the same battery bay geometry, connector pinout, and BMS handshake protocol — one cell covers both. The 82.60 × 61.00 × 4.30mm footprint sits flush in either chassis without pressure on the back cover.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Xenium S326 unit. The BMS accepted the charge IC handshake on the first cycle, and protection thresholds for overvoltage and overcurrent triggered correctly at expected limits.
- Fuel gauge recalibration on first install: After fitting this cell, run one full discharge to automatic shutdown, then charge uninterrupted to 100% with fast charging disabled. This gives the fuel gauge IC one clean reference cycle against the new cell's discharge curve before high-current charging begins.
Sudden shutdown at 20–30% on the Xenium S326
This happens because the fuel gauge IC was calibrated against the old cell's internal resistance and discharge curve. The new cell hits a voltage cliff under modem or display load — dropping below the system cutoff threshold — while the OS still reports 20–30% remaining. The gauge and the actual cell state are out of sync. One full discharge-to-shutdown followed by an uninterrupted charge to 100% resets the coulomb counter and eliminates the mismatch. After that cycle, shutdowns at false-high percentages stop.
USB fast charge not activating after battery replacement
The Xenium S326 charge IC uses a handshake sequence to enable fast charge mode on every boot and on each new charge session. With a new cell at low state of charge, the BMS may return an out-of-range impedance reading on the first cycle, causing the charge IC to fall back to standard 5V charging. This is not a fault — it clears after the first complete charge cycle. Plug in via the original cable, let it charge fully at standard rate, and fast charge will activate normally on the next session.