About this replacement
HP Chromebook 13 G1 — 11.4V Li-Polymer Replacement Battery (SD03XL)
This is an 11.4V 3900mAh (44.46Wh) lithium-polymer replacement battery for the HP Chromebook 13 G1. It fits the full G1 lineup including the W4M19EA, X8C55US, and W6S33AA variants. OEM part numbers include SD03XL, HSTNN-IB7K, 847462-1C1, and TPN-Q176.
- Chromebook 13 G1 fitment: All G1 variants share the same three-cell Li-Polymer pack running an 11.4V nominal rail. The connector pinout, BMS communication protocol, and physical footprint are identical across the lineup — one cell fits every G1 configuration listed.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a G1 unit. The BMS handshake completed without fault codes, charge acceptance reached rated capacity, and the EC controller recognised the cell without triggering unknown-battery warnings.
- Post-install calibration on the Chromebook 13 G1: After fitting, let the battery drain fully to hibernate cutoff, then charge uninterrupted to 100%. This forces ChromeOS and the embedded controller to re-learn the new cell's discharge curve and clears the inaccurate health warning that appears after every cell swap.
Why the Chromebook 13 G1 shuts down at 20–30% after a battery swap
The G1's embedded controller uses a fuel gauge IC that tracks charge state against the old cell's learned discharge curve. When a new cell goes in, that curve no longer matches reality. At around 20–30% shown, the voltage under CPU and display load drops faster than the stale model predicts, and the EC triggers an emergency shutdown to protect the cell. Running one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100% resets the learn cycle. After two to three calibration cycles, the reported percentage tracks the actual cell state accurately.
BIOS reporting battery health as poor or unknown after replacement
The G1's firmware reads battery health data from the cell's EEPROM on every boot. A new cell carries different EEPROM values than the original — cycle count, rated Wh, and charge history — which the BIOS interprets as degraded or unrecognised hardware. This is a data mismatch, not a fault with the replacement cell. Run a full discharge-to-hibernate cycle, then charge to 100% without interruption. The embedded controller rewrites its internal health model against the new cell's actual parameters, and the poor-health flag clears within one to two cycles.