About this replacement
Philips Xenium I999 — 3.8V Li-Polymer Replacement Battery (AB3000EWML)
This 3.8V, 2900mAh lithium-polymer battery replaces the original AB3000EWML cell in the Philips I999 and Xenium I999 smartphones. It fits directly into the existing battery bay and connects via the stock connector. Use the capacity figure from this listing — 2900mAh — not third-party sources.
- I999 and Xenium I999 fitment: Both model variants use the same battery bay geometry, connector pinout, and BMS handshake protocol. One cell covers both.
- Bench tested on actual hardware: We ran the AB3000EWML cell through charge and discharge cycles on the Xenium I999 platform. The BMS accepted the cell without error flags, and the charge IC completed a full cycle without thermal events.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and let the phone run through one complete discharge-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before fast charge current is applied to an uncalibrated cell.
Why the Xenium I999 reports wrong battery percentage after a cell swap
The fuel gauge IC on the I999 stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches actual cell behaviour — the IC reports percentage against the old data. This shows up as jumpy readings or a percentage that doesn't match real charge state. One full discharge down to automatic shutoff, followed by an uninterrupted charge to 100%, forces the IC to relearn the curve against the new cell. After that cycle, percentage readings stabilise.
Sudden shutdown at 20–30% on the replacement cell
This happens when the modem radio or screen backlight pulls a current spike the cell cannot sustain at that state of charge — voltage drops below the BMS cutoff threshold instantly, and the phone shuts off before the percentage gauge catches up. It is a voltage cliff, not a capacity fault. It is most common before the fuel gauge IC has completed its first recalibration cycle. Run one full discharge-charge cycle and check whether shutoffs persist below 3.6V under load.