About this replacement
Asus VivoBook Flip 14 TP412UA Series — 11.55V Li-Polymer Replacement Battery (C31N1733)
This is a Li-Polymer replacement battery for the Asus VivoBook Flip 14 TP412UA series 2-in-1 convertible laptop. It fits models including the EC034T, EC075T, EC173T, and EC036T variants. Rated at 11.55V and 3550mAh (41Wh), it matches the OEM specification under part numbers C31N1733, 0B200-02970000, and 0B200-02970100.
- TP412UA series compatibility: All TP412UA variants share the same 11.55V three-cell architecture, connector pinout, and BMS handshake protocol. The power management IC on this board authenticates via the same EEPROM signature across the full EC-suffix range, so one cell fits the entire lineup.
- Bench tested on actual hardware: We ran this cell on a TP412UA board and confirmed the BMS completed its handshake without fault codes. The charge controller accepted the cell and stepped through its CC/CV charge stages correctly with no thermal cutoff events.
- Post-install calibration on the TP412UA: 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 and clears the inaccurate health warning that typically appears after a cell swap on this platform.
TP412UA shutting down at 20–30% shown on the fuel gauge
This happens when the fuel gauge IC is still calibrated to the old degraded cell. The new cell has a steeper voltage curve than the worn one, so the IC misreads state-of-charge and triggers shutdown long before the cell is actually depleted. The fix is a full calibration cycle: discharge to automatic hibernate, do not force power off early, then charge to 100% without interruption. After two or three of these cycles, the gauge IC maps the new cell's voltage curve and the shutdowns stop.
BIOS reporting battery health as "poor" or "replace" immediately after swap
The Asus BIOS reads health status from EEPROM data written by the old cell's onboard fuel gauge — it does not re-evaluate the physical cell on first boot. Until the battery learn cycle completes, the system displays the previous cell's degraded health record. Run the TP412UA's built-in battery calibration: hold the power button off, plug in AC power, and let it charge fully before booting. One complete charge–discharge–charge sequence overwrites the stale EEPROM health data and clears the warning. After the cycle, the BIOS should read the health status against 41Wh and report correctly.