About this replacement
HP EliteBook 1050 G1 — 15.4V Li-ion Replacement Battery (ZG04XL)
This is a 15.4V, 4000mAh (61.6Wh) Li-ion replacement battery for the HP EliteBook 1050 G1 notebook. It cross-references OEM part numbers ZG04XL, HSTNN-IB8I, L07046-855, and L07352-1C1. It fits the full EliteBook 1050 G1 range, including the 4QY20EA, 4PH83PC, and 4QY53EA variants.
- EliteBook 1050 G1 platform fit: All EliteBook 1050 G1 variants share the same 15.4V four-cell architecture, connector pinout, and BMS handshake protocol. Swapping between SKUs within the 1050 G1 line does not change battery compatibility — the same cell works across the entire model family.
- Bench tested on actual hardware: We ran this cell on an EliteBook 1050 G1 and confirmed the BMS handshake completed cleanly, BIOS accepted the battery without fault flags, and charge cycling stepped through all stages without interruption at the expected voltage thresholds.
- Post-install calibration on the EliteBook 1050 G1: After fitting this battery, run one full discharge to hibernate-cutoff, 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 immediately after fitting a new cell
The EliteBook 1050 G1 stores battery health history in EEPROM on the old cell. When a new cell arrives, the BIOS reads no cycle history and flags the battery as degraded or unknown. This is not a fault with the replacement — it is a data mismatch between the new cell's EEPROM and the laptop's stored expectations. Run a full discharge-to-hibernate followed by an uninterrupted charge to 100% to allow the BIOS learn cycle to write fresh data to the new cell's EEPROM.
EliteBook 1050 G1 shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual chemistry. The percentage reading is based on stale data from the previous cell, so the displayed figure and the real state-of-charge diverge under full CPU and display load. When voltage drops below the BMS cutoff threshold, the laptop shuts down even though the gauge still shows remaining charge. Complete two to three full discharge-and-charge cycles — the fuel gauge IC recalibrates progressively and the shutdowns stop once it tracks the new cell accurately.