About this replacement
Asus Transformer Book T100TAL — 3.85V Li-Polymer Replacement Battery (C12N1406)
This 3.85V, 8000mAh (30.8Wh) Li-Polymer battery replaces the C12N1406 cell in the Asus Transformer Book T100TAL series. It fits the tablet unit of the T100TAL hybrid — the screen-and-board half that detaches from the keyboard dock. Voltage and connector match the original spec exactly.
- T100TAL series fitment: The T100TAL, T100TAL-DK008P, T100TAL-1K, and Pad Transformer Book T100TAL all use the same 3.85V battery bay, BMS connector pinout, and charge IC handshake. One cell fits the full range.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the T100TAL platform. The BMS accepted the new cell without fault codes, and the charge IC completed a full cycle without thermal cutoff or negotiation failure.
- Fuel gauge recalibration after swap: After fitting this battery, run the tablet down to automatic shutoff — do not force power-off — then charge uninterrupted to 100%. This gives the fuel gauge IC a full reference cycle against the new cell and clears inaccurate percentage readings that appear straight after installation.
Why the T100TAL shuts down at 15–25% remaining
The T100TAL combines display, SoC, and Wi-Fi on a single power rail drawn from this battery. Under combined load — screen at full brightness plus active Wi-Fi — current draw spikes and battery voltage sags below the BMS cutoff threshold before the percentage counter reaches zero. The fuel gauge IC reads state-of-charge from a model calibrated to the old cell, so the reported percentage is already off. One full discharge-to-shutoff and uninterrupted recharge cycle resets that model against the new cell and typically pushes the shutdown point back below 5%.
Fast charging not available after battery replacement
The T100TAL's charge IC uses a handshake protocol to confirm battery state before enabling higher charge rates. On a freshly installed cell with no charge history, the IC defaults to a conservative rate until it completes one accepted full cycle. This is not a fault with the battery or the charger. Use the original Asus adapter, let the first charge run to 100% without interruption, and fast-charge capability will be available from the second cycle onward.