ARM N243 14.8V Replacement Battery 4400mAh Li-ion

ARM N243 / N244 Series — 14.8V Li-ion Replacement Battery (23-U74201-31)

This is a 14.8V, 4400mAh (65.12Wh) Li-ion battery for the ARM N243 and N244 series notebooks. It replaces OEM part numbers including 23-U74201-31, UN243, UN243S, and BAT-243S1. If the original cell no longer holds a charge or the OS reports degraded health, this cell restores normal operation.

• N243 and N244 platform fit: Both series run the same 14.8V four-cell Li-ion architecture with identical connector pinout and BMS handshake protocol, which is why a single cell covers both lines. The BMS reads pack identity from the EEPROM on first boot — no hardware modification needed.
• Bench tested on actual hardware: We cycled this cell through charge, full-load discharge, and BMS cutoff on N243 hardware. The protection circuit tripped correctly at low-voltage cutoff, and the charge controller accepted the cell without error flags after a full learn cycle.
• Post-install calibration on the N243: After fitting, run one complete discharge until the notebook hibernates on its own, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after a cell swap — skipping this step leaves the fuel gauge IC reading from stale EEPROM data.

BIOS reporting poor battery health immediately after swap on the N243

When the N243 BIOS flags a new cell as "poor health" or "replace battery" straight after installation, the fault is almost always stale EEPROM data carried over from the old pack — not a problem with the new cell. The fuel gauge IC compares measured capacity against the rated value stored in firmware and raises a flag when they don't align. Run one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100% to let the BIOS re-learn the actual cell capacity. After two to three cycles the health indicator should normalise and report accurately.

N243 shutting down abruptly at 20–30% shown on the fuel gauge

This happens when the cell voltage drops below the BMS cutoff threshold under combined CPU and display load before the fuel gauge predicts it should. It is a calibration gap — the gauge IC is still using capacity estimates from the previous degraded cell. The cell voltage at that shutdown point is typically around 14.0–14.2V under load, which the BMS correctly treats as low-voltage cutoff even though the percentage shown looks safe. Run the full discharge-calibration cycle described above; after one or two passes the gauge tracking should align with actual cell behaviour and the premature shutdowns will stop.