About this replacement
Asus G74 Series — 14.4V Li-ion Replacement Battery (A42-G74)
This is a 14.4V, 4400mAh (63.36Wh) Li-ion replacement battery for the Asus G74 gaming laptop series. It fits the G74, G74J, G74JH, G74JH-A1, and over 21 additional G74 variants. The OEM part numbers it replaces are A42-G74, ICR18650-26F, and LC42SD128.
- G74 series battery platform: All G74 variants use the same 14.4V four-cell configuration, shared connector pinout, and BMS communication protocol — which is why one cell covers the full model range without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a G74JH. The BMS handshake completed correctly, charge termination triggered at 16.8V, and the protection circuit tripped as expected at the low-voltage cutoff threshold.
- Post-install calibration on the G74: After fitting this battery, run a full discharge until the laptop hibernates, then charge uninterrupted to 100% without use. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after installing a new G74 cell
The G74 BIOS reads health data stored in the battery's EEPROM — not live cell voltage. When you swap in a new cell, the EEPROM still contains wear data written by the old pack, so the BIOS flags it as degraded even though the chemistry is fresh. The fix is a full learn cycle: discharge to hibernate cutoff, then charge to 100% in one uninterrupted session. After two to three cycles, the fuel gauge IC recalibrates against the new cell and the health status corrects itself.
G74 shutting down at 20–30% battery remaining shown on screen
This happens when the cell voltage drops below the BMS cutoff threshold under load before the fuel gauge expects it — a voltage cliff caused by a mismatch between the gauge IC's stored discharge curve and the actual cell. On a fresh replacement, this is almost always a calibration issue, not a defective cell. Run one full discharge to hibernate without interruption, then charge to 100%. If the shutdown point still drifts, check that Battery Care Mode or any charge-limiting setting in MyASUS is disabled, then repeat the calibration cycle.