A42-G750 Asus G750 Replacement Battery 14.8V 4800mAh

Asus G750 Series — 14.8V Li-ion Replacement Battery (A42-G750)

The A42-G750 is a 14.8V, 4800mAh (71.04Wh) Li-ion battery for the Asus G750 gaming laptop series. It fits the G750J, G750JH, G750JM, and over a dozen related G750 variants. Install it when the original cell no longer holds a charge or the laptop fails to run unplugged.

• G750 series compatibility: All G750 variants in this family share the same 14.8V four-cell architecture and A42-G750 connector pinout. The BMS handshake uses the same EEPROM communication protocol across the entire line, so one cell works across all listed models without hardware modification.
• Bench tested on actual hardware: We ran this battery through full charge and discharge cycles on a G750JH. The BMS accepted the cell without fault flags, charge current stepped down correctly at 80% and 95%, and the protection circuit tripped cleanly at the low-voltage cutoff threshold.
• First-cycle calibration on the G750: 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 typically appears after every cell swap on this platform.

BIOS reporting battery health as poor immediately after fitting the A42-G750

The G750 BIOS reads health data from the battery's EEPROM, which stores cycle count and rated capacity from the previous cell. A new A42-G750 arrives with factory EEPROM values that don't match the BIOS's stored baseline, triggering a false poor-health flag. This isn't a fault with the replacement cell — it's a data mismatch. Run one complete discharge-to-hibernate cycle followed by an uninterrupted full charge. After two to three cycles the fuel gauge IC recalibrates against the new cell and the health warning clears.

Laptop shuts down at 20–30% charge shown on the G750

This happens when the cell cannot sustain voltage under the combined load of the G750's CPU, discrete GPU, and high-brightness display. At that charge level, internal resistance causes a voltage cliff — the cell drops below the BMS cutoff threshold faster than the fuel gauge can track. The percentage shown is the gauge's last reading before shutdown, not the true state of charge. To confirm the cell is healthy, charge to 100%, disconnect the adapter, and run a GPU benchmark — if the system holds above 14.2V under load at 25% remaining, the cell is within spec.