About this replacement
HP Elite X360 1040 14 G10 — 11.55V Li-Polymer Replacement Battery (WQ03XL)
This 11.55V, 3050mAh (35.23Wh) lithium-polymer cell replaces the original battery in the HP Elite X360 1040 14 G10, Elite X360 830 G10, and EliteBook 835 13 Inch G10. All three are business-class convertibles that share the same battery bay geometry, connector pinout, and BMS handshake protocol. OEM part numbers covered include WQ03XL, 996QA243H, HSTNN-AB1C, and N22347-002, among others listed above.
- Elite X360 and EliteBook 835 G10 platform fit: These models share a common 11.55V three-cell Li-Polymer architecture with identical SMBus communication lines. The BMS firmware on each device addresses the same register set, so one cell works across all three without connector modification or firmware adaptation.
- Bench tested on actual hardware: We ran this cell on an Elite X360 1040 14 G10 and logged the BMS handshake at initial charge. The cell authenticated correctly, charge current stepped through pre-charge and CC phases without interruption, and the protection circuit responded to a controlled over-discharge event at the expected 9.0V cutoff threshold.
- First-cycle calibration on the Elite X360 platform: After installing this cell, discharge the laptop to hibernate cutoff under normal workload — do not force shutdown — then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health flag that HP's embedded controller sets automatically after every cell swap.
Why the Elite X360 BIOS reports poor battery health immediately after a cell swap
HP's embedded controller stores charge history and health data in an EEPROM register tied to the original cell. When a new cell is installed, that stored data does not match the new cell's reported state, and the controller flags the battery as degraded before it has cycled once. This is not a fault with the replacement cell — it is a mismatch between old EEPROM values and fresh chemistry. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% forces the BIOS to rewrite the learn cycle data against the new cell. After that cycle, the health warning clears and the fuel gauge reads accurately.
Laptop shuts down at 20–30% charge shown on screen
This happens when the cell voltage drops below what the CPU and display together can sustain under full load — the voltage cliff arrives earlier than the fuel gauge predicts. The fuel gauge IC is still working from calibration data built against the old, degraded cell, so its percentage readings are shifted. Under peak load, actual cell voltage hits the BMS cutoff threshold while the OS still shows 20–30% remaining. Recalibrate the gauge by running one full discharge under a real workload until the laptop hibernates, then charge to 100% without interruption — the gauge will re-anchor to the new cell's actual voltage curve.