About this replacement
Asus ZenBook 15 UX533FD — 15.4V Li-Polymer Replacement Battery (C41N1814)
This is a 15.4V, 4700mAh (72.38Wh) Li-Polymer battery for the Asus ZenBook 15 UX533FD and UX533 series notebooks. It replaces OEM part numbers C41N1814, C41PpEH, and 0B200-03120100. The battery slots into the UX533FD chassis and connects to the same 4-cell battery management circuit the original cell uses.
- UX533 series compatibility: The UX533FD, UX533FDA, and their retail variants all share the same 15.4V four-cell battery bay, connector pinout, and BMS handshake protocol. That common architecture is why one cell part number covers the full range.
- Bench tested on actual hardware: We cycled this cell through charge, full-load discharge, and BMS communication checks on a ZenBook 15 board. The protection circuit tripped correctly at low-voltage cutoff and the charge IC resumed without fault codes.
- Post-install discharge cycle: After fitting this cell, run one full discharge to hibernate cutoff, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity curve and clears the inaccurate health warning that appears after every cell swap.
Why the ZenBook 15 shuts down at 20–30% after a battery swap
The fuel gauge IC inside the UX533FD stores a learned discharge curve from the previous cell. When a new cell goes in, the IC still uses that old curve to estimate remaining capacity. Under full CPU and display load, actual cell voltage drops faster than the stale model predicts — the laptop hits the hardware low-voltage cutoff while the OS still shows 20–30% remaining. Running two or three complete discharge-to-hibernate, charge-to-full cycles forces the fuel gauge to rebuild its model against the new cell's real voltage behaviour. After calibration, the shutdowns stop and the percentage readout tracks accurately.
BIOS reporting battery health as poor immediately after replacement
The BIOS reads battery health data from an EEPROM register that the old cell wrote to over its lifetime. A fresh cell arrives with either blank or factory-default EEPROM values, which the BIOS interprets as a degraded or unknown battery. This is a data mismatch — not a fault with the new cell. Complete the full discharge-then-charge calibration cycle described above. After one to two full cycles, the BIOS battery health indicator updates to reflect the new cell's actual state and the poor-health flag clears.