Sony Xperia T2 Ultra Replacement Battery 3.8V 3000mAh AGPB012-A001

Sony Xperia T2 Ultra D5303 — 3.8V Li-Polymer Replacement Battery (AGPB012-A001)

This is a 3.8V, 3000mAh Li-Polymer replacement battery for the Sony Xperia T2 Ultra, covering D5303 and dual-SIM variants. It matches the OEM cell footprint at 86.10 × 73.55 × 3.50mm and uses part number AGPB012-A001 (also sold as LIS1554ERPC). Fit this when the original cell no longer holds a charge or the phone shuts down unexpectedly under load.

• D5303 and dual-SIM coverage: The T2 Ultra single and dual-SIM variants share the same battery bay geometry, connector pinout, and BMS handshake voltage — one cell fits both. No adapter or wiring change needed.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a D5303 unit. The BMS accepted the new cell without flagging an incompatibility error, and charge current stepped correctly from pre-charge to CC/CV phases.
• Fuel gauge recalibration on first use: After fitting, disable any fast-charge app or charger for the first complete discharge-to-charge cycle. This gives the Xperia T2 Ultra's fuel gauge IC time to map its coulomb counter against the new cell's actual discharge curve before high-current charging begins.

Why the Xperia T2 Ultra reports wrong battery percentage after a cell swap

The T2 Ultra uses a coulomb-counting fuel gauge IC that builds its model against the original cell's internal resistance and capacity curve over time. When you swap in a new cell, the IC still references the old learned model, so the percentage shown on screen does not match actual charge state. The fix is one full uninterrupted discharge down to automatic shutdown, followed by a full charge to 100% without interruption. After that cycle, the IC resets its baseline and percentage accuracy returns to normal.

Sudden shutdown at 20–30% on the replacement cell

This happens when the phone's modem or display draws a current spike the new cell cannot sustain without dropping below the BMS cutoff voltage — typically around 3.0V per cell. A fresh Li-Polymer cell can have slightly higher internal resistance in early cycles, making voltage sag worse under peak load. The fuel gauge IC still shows 20–30% remaining because it reads state of charge, not instantaneous voltage under load. Let the phone run through three to five full cycles; internal resistance drops as the cell conditions, and the shutdowns should stop.