Asus Transformer Pad 3G Replacement Battery C11P1328 3.8V

Asus Transformer Pad TF103CG — 3.8V Li-Polymer Replacement Battery (C11P1328)

This is a 3.8V, 5000mAh Li-Polymer replacement battery for the Asus Transformer Pad 3G series, including the TF103CG and TF0310CG. It replaces OEM part numbers C11P1328, C11Pq2H, and 0B200-00980000M. Fits the tablet unit — not the keyboard dock.

• TF103CG and TF0310CG compatibility: Both models run the same 3.8V power rail, use the same connector pinout, and share the same BMS handshake protocol — one cell covers the full range without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a TF103CG unit. The BMS accepted the charge handshake on first connection, balanced correctly across the protection circuit, and held voltage within spec at full load.
• Fuel gauge recalibration after swap: After fitting this battery, run the tablet down to automatic shutoff — do not force-restart — then charge uninterrupted to 100%. This gives the fuel gauge IC a full reference cycle against the new cell and eliminates the inaccurate percentage reading that commonly appears after a swap.

Why the Transformer Pad shuts down at 15–25% remaining

The TF103CG drives its display, WiFi radio, and CPU from a single power path. Under combined load, voltage sags faster than the fuel gauge IC expects based on calibration data from the old, degraded cell. The BMS interprets this sag as a low-voltage cutoff condition and triggers shutdown — even though capacity remains. One full discharge-to-shutoff cycle followed by an uninterrupted charge resets the reference curve. After that cycle, shutdowns at 15–25% stop.

Fast charging not available after battery replacement

The Transformer Pad's charge IC negotiates charging rate during the first accepted charge cycle. Until that handshake completes successfully, the system defaults to slow charge as a protective fallback. This is not a fault with the replacement cell. Use the original Asus charger, connect at a low state of charge, and let the first cycle complete fully without interruption. Fast charge availability is typically restored from the second cycle onward.