About this replacement
HP Split X2 13-M000 — 11.1V Li-Polymer Replacement Battery (WR03XL)
This is an 11.1V, 2850mAh (31.64Wh) Li-Polymer battery for the HP Split X2 13-M000 convertible laptop. It replaces OEM part WR03XL and also covers STNN-IB5J, HSTNN-IB5J, TPN-Q133, and related part numbers. Fit extends to the Split 13-M114TU X2 and Pavilion 13-p100el X2 among others.
- Split X2 platform compatibility: These models share the same 11.1V three-cell voltage rail, slim 4.40mm cell stack, and connector pinout. The BMS handshake uses the same EEPROM identifier across the 13-M000 series, so the replacement communicates with the firmware without modification.
- Bench tested on actual hardware: We ran this cell through charge, discharge, and BMS communication checks on the Split X2 platform. The protection circuit tripped correctly at low-voltage cutoff and the charge controller accepted the cell without fault codes on reconnection.
- First-cycle calibration on the Split X2: After installing, run one full discharge until the laptop hibernates, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.
BIOS reporting poor battery health after installing a new cell
The HP Split X2 stores battery wear data in EEPROM on the old cell. When you swap the cell, the BIOS reads zero charge cycles but may still flag health as poor or unknown because the fuel gauge IC has not yet mapped the new cell's actual capacity curve. This is a firmware calibration state, not a fault with the replacement. One complete discharge-to-hibernate followed by an uninterrupted full charge gives the BIOS enough data to update its health status. After two to three cycles the health reading stabilises.
Laptop shuts down at 20–30% charge shown after battery swap
This happens because the fuel gauge IC is still using the old cell's discharge curve to estimate remaining capacity. The new cell hits a voltage cliff under combined CPU and display load before the gauge reaches zero, so the system shuts down with charge still shown. The fix is the same learn cycle — discharge fully to hibernate cutoff, then charge to 100% without interruption. After two calibration cycles the gauge tracks the new cell accurately and shutdowns at false percentages stop.