About this replacement
HP EliteBook 745 G3 — 11.4V Li-Polymer Replacement Battery (CS03XL)
This 11.4V, 3400mAh (38.76Wh) lithium-polymer cell replaces the CS03XL battery in the HP EliteBook 745 G3 and its variants, including L9Z80AV and L9Z81AV. It matches the original connector, physical footprint (198.10 × 102.50 × 6.60 mm), and BMS handshake required by the EliteBook 745 G3 platform. Cross-references include 800231-141, 800513-001, HSTNN-IB6Y, and T7B32AA.
- EliteBook 745 G3 platform fit: The 745 G3 shares its battery slot, 11.4V rail, and SMBus BMS protocol with several L9Z-series configurations. All use the same CS03XL connector and cell count, so one cell covers the full variant range without modification.
- Bench tested on actual hardware: We ran this cell on an EliteBook 745 G3 board. The BMS completed the handshake on first insertion, BIOS detected the cell without error, and the charge controller accepted a full charge cycle without interruption.
- Post-install calibration on the 745 G3: After installing, 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 cell replacement.
BIOS reporting poor battery health after replacement on the EliteBook 745 G3
The EliteBook 745 G3 stores battery health data in EEPROM on the original cell. When a new cell is installed, the BIOS reads no cycle history and flags the battery as degraded or unknown. This is not a fault with the replacement cell — it is the BIOS comparing an empty data register against its expected values. Running one full discharge-to-hibernate followed by a complete uninterrupted charge gives the BIOS enough data to re-establish its learn cycle and clear the warning.
EliteBook 745 G3 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 discharge curve. The IC predicts shutdown based on data from the old, degraded cell, so its voltage cliff estimate is too early. The laptop cuts power before the display percentage reaches zero because the cell voltage drops below the BMS floor faster than the uncalibrated gauge expects. Two to three full discharge-and-charge cycles recalibrate the IC — after that, shutdowns should align with the gauge reading below 5%.