About this replacement
Samsung Chromebook XE303C12 — 7.5V Li-Polymer Replacement Battery (AA-PBZN2TP)
This is a 7.5V, 4080mAh (30.6Wh) lithium-polymer replacement battery for the Samsung Chromebook XE303C12 and Chromebook Series 3. It also fits the ATIV Smart PC 500T line. OEM part numbers AA-PBZN2TP and BA43-00355A both map to this cell.
- XE303C12 and Series 3 platform fit: These models share the same 7.5V power rail, flat Li-Polymer form factor, and connector pinout. The BMS on each expects the same charge termination voltage, so the same cell works across the full family without modification.
- Bench tested on actual hardware: We ran this cell in an XE303C12 chassis and confirmed BMS handshake, correct charge termination at 8.7V, and stable discharge through a full CPU and display load cycle. No false cutoff events triggered.
- Post-install calibration on the XE303C12: After fitting this battery, run the Chromebook down until it hibernates, then charge uninterrupted to 100%. This resets the EC battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.
Why the XE303C12 shuts down at 20–30% after a battery swap
The Chromebook's embedded controller tracks cell voltage curves from the previous battery. After a swap, it still uses those old voltage thresholds to estimate state of charge. When the new cell hits a voltage point the EC associates with near-empty, it triggers shutdown — even if actual capacity remains. This is not a fault with the replacement cell. One full discharge-to-hibernate followed by a full uninterrupted charge teaches the EC the new cell's curve and eliminates premature shutdowns.
ChromeOS fuel gauge reading 0% or "unknown" immediately after install
The fuel gauge IC on the XE303C12 reads EEPROM data written by the original cell to calculate charge state. A new cell arrives with different EEPROM baseline values, so the gauge reports 0% or unknown until it collects real discharge data. This is a calibration gap, not a dead battery. Plug in, let it charge fully, then discharge to hibernate once — the fuel gauge IC recalibrates against the new cell's actual chemistry and the readout stabilises within two cycles.