About this replacement
Asus TP201SA Series — 11.4V Li-ion Replacement Battery (B31N1536)
This is an 11.4V 4150mAh (47.31Wh) Li-ion battery for the Asus TP201 and TP201SA VivoBook Flip hybrid. It fits the TP201SA-FV0027D, TP201SA-FV0007T, and over a dozen additional TP201SA variants. The OEM part numbers it replaces are B31N1536 and 0B200-02040000.
- TP201SA series compatibility: All TP201SA models share the same 11.4V three-cell configuration, connector pinout, and BMS handshake protocol. That common electrical architecture means one battery covers the full production run of this hybrid line without firmware conflicts or connector mismatch.
- Bench tested on actual hardware: We cycled this cell through charge, full load discharge, and BMS cutoff on a TP201SA unit. The BMS communicated state-of-charge correctly, charge termination triggered at the expected 12.6V ceiling, and no fault flags were thrown during the draw-down phase.
- Post-install calibration on the TP201SA: After fitting, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.
BIOS reporting poor battery health immediately after fitting a new cell
The TP201SA's BIOS reads health data from EEPROM registers carried over from the old cell, not from the physical chemistry of the new one. Until a learn cycle overwrites those registers, the system reports the new battery as degraded or unknown. This is a firmware state problem, not a cell defect. Run a full discharge to hibernate-cutoff followed by an uninterrupted charge to 100% — most units clear the health warning within two cycles.
TP201SA shutting down at 20–30% charge shown on screen
The fuel gauge IC on this platform was calibrated against the original cell's discharge curve. A new cell has a slightly different voltage-to-capacity slope, so the gauge reads 20–30% remaining when the cell voltage has already dropped below the load-sustain threshold under full CPU and display draw. The system shuts down to protect the cell, even though the gauge says charge remains. Two full calibration cycles — complete discharge to cutoff, full uninterrupted recharge — align the fuel gauge IC to the new cell's actual curve and eliminate the early shutdown.