About this replacement
Samsung ATIV Book 7 NP740U3E — 7.6V Li-Polymer Replacement Battery (AA-PBWN4AB)
This is a 7.6V, 7500mAh (57Wh) lithium-polymer replacement battery for the Samsung ATIV Book 7 series, including the NP740U3E and NP740U3E-S02UK. It replaces OEM part numbers AA-PBWN4AB and BA43-00360A. The cell fits the slim chassis of the NP740 line and connects to the same power management circuit as the original.
- NP740 series compatibility: The NP740U3E and related NP740 variants share the same battery bay depth, connector pinout, and 7.6V nominal voltage rail. The BMS handshake protocol matches across this generation, so the replacement communicates correctly with Samsung's EC firmware without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an NP740U3E unit. The BMS accepted the cell without rejecting it as unknown, charge current ramped normally through CC and CV phases, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
- Post-install calibration on the NP740: After fitting this battery, run one full discharge until the laptop hibernates on its own, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears on first boot after any cell swap.
Why the NP740U3E shuts down at 20–30% after a battery swap
The ATIV Book 7's fuel gauge IC builds a discharge model from the previous cell's EEPROM data. When a new cell goes in, that model no longer matches actual cell chemistry, and the voltage-to-capacity mapping is off. Under full CPU and display load, the measured voltage drops sharply — the firmware reads this as a critical low-battery condition and triggers an emergency shutdown even though charge remains. Two full discharge-to-hibernate and recharge cycles recalibrate the fuel gauge IC against the new cell's actual voltage curve and stop the early shutdowns.
BIOS showing battery health as "poor" or "replace now" after fitting a new cell
Samsung's BIOS reads battery health metrics stored in the cell's EEPROM — cycle count, rated capacity, and internal resistance figures carried over from the old battery. A new cell arriving with default EEPROM values can trigger a false "poor health" or "battery needs replacement" warning on first boot. This is a reporting mismatch, not a defect. Run the battery learn cycle — one full discharge to hibernate-cutoff followed by an uninterrupted charge to 100% — and the BIOS will update its health register against the new cell's actual data. Check the Samsung Battery Manager after the first full cycle to confirm the warning has cleared.