About this replacement
Philips Xenium CTX588 / X588 / S386 — 3.8V Li-Polymer Replacement Battery (AB5000BWMC)
This is a 3.8V, 4900mAh (18.62Wh) Li-Polymer cell replacing OEM part AB5000BWMC. It fits the Philips Xenium CTX588, X588, S386, and CTS386 smartphones. Install it when the original cell no longer holds a charge through a normal day of calls, messaging, and screen-on use.
- CTX588 / X588 / S386 / CTS386 platform fit: These four models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The AB5000BWMC footprint — 81.00 × 64.30 × 5.30mm — seats correctly in all four without modification.
- Bench tested on actual hardware: We ran charge cycles through the Philips charge IC and confirmed the BMS communicates state-of-charge data correctly, accepting both standard and fast-charge current profiles without tripping a protection cutoff.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated register — preventing erratic percentage readings from the first day.
Why the Xenium CTX588 reports wrong battery percentage after a cell swap
The Philips Xenium fuel gauge IC stores a discharge curve built around the original cell's impedance and capacity profile. When a new cell goes in, that stored curve no longer matches the physical cell. The gauge reads voltage correctly but maps it to the wrong state-of-charge value. One full discharge down to auto-shutdown followed by a complete charge forces the coulomb counter to relearn the curve against the new 4900mAh cell.
Sudden shutdown at 20–30% on the replacement cell
This happens when the phone's modem or display draws a high burst of current and the cell voltage sags below the BMS protection threshold faster than the gauge predicts. The gauge still reads 20–30% but the actual cell voltage under load has already dropped past the cutoff point. It is not a faulty battery — it is the fuel gauge IC running an uncalibrated curve against a fresh cell. Run two complete discharge-charge cycles and the reported percentage at shutdown will shift closer to 5–8%.