Asus VivoTab Smart ME400C C12-TF400C Compatible Battery 3.7V 6750mAh

Asus VivoTab Smart ME400C — 3.7V Li-Polymer Replacement Battery (C12-TF400C)

This is a 3.7V, 6750mAh Li-Polymer battery built to the C12-TF400C specification. It fits the Asus VivoTab Smart ME400C and the Transformer Pad TF502T, TF600T-1B016R, TF600TG-1B015R, and over a dozen additional variants. The connector, contact layout, and BMS handshake protocol match the original across all listed models.

• ME400C and Transformer Pad platform compatibility: These tablets share the same battery bay dimensions, the same 3.7V charge rail, and an identical 5-pin BMS communication line. The charge IC on each device reads cell state through that line — the same firmware path works across all listed models without modification.
• Bench tested on actual hardware: We cycled this cell on the ME400C charge controller and confirmed the BMS handshake established within the first charge cycle. The protection circuit tripped correctly at undervoltage and reset cleanly on reconnect.
• Fuel gauge recalibration after swap: After installing this battery, run the tablet down to automatic shutoff — do not force a shutdown — then charge uninterrupted to 100%. The ME400C's fuel gauge IC calibrates its reference curve against the old cell. One full discharge-to-charge cycle resets it against the new cell and corrects the inaccurate percentage readings that typically appear in the first few sessions.

VivoTab Smart ME400C shutting down at 15–25% remaining

This happens when the fuel gauge IC still holds the discharge curve of the old, degraded cell. As the new cell voltage drops under combined display and Wi-Fi load, the reported percentage diverges from actual cell voltage — the tablet hits the low-voltage cutoff threshold before the OS percentage reaches zero. The fix is one complete recalibration cycle: discharge to automatic shutoff, then charge to 100% without interruption. After that cycle, the cutoff aligns correctly with the new cell's actual 3.7V baseline.

Tablet warm to the touch during the first few charges

The ME400C's charge IC runs a conditioning pass on a new Li-Polymer cell during the first two or three cycles — charge current is slightly higher than steady-state maintenance charging. Surface warmth during this period is the charge controller working normally, not a fault. If the tablet becomes hot rather than warm, or if charging stops and restarts repeatedly, check that the charge port is clear and that ambient temperature is below 35°C. Warmth should reduce noticeably by the third full charge cycle.