Sony Xperia XA1 Ultra LIP1641ERPC Replacement Battery 3.8V 2700mAh

Sony Xperia XA1 Ultra — 3.8V Li-Polymer Replacement Battery (LIP1641ERPC)

This 3.8V, 2700mAh lithium-polymer cell replaces the factory battery in the Sony Xperia XA1 Ultra and XA1 Ultra Dual TD-LTE (G3226 and Redwood DS variants included). It matches the OEM part numbers LIP1641ERPC and LIP1641ERPXC. Physical dimensions are 93.10 × 51.62 × 3.80mm — a direct size match for the XA1 Ultra battery bay.

• XA1 Ultra platform fit: The XA1 Ultra, XA1 Ultra Dual TD-LTE, G3226, and Redwood DS all share the same battery cavity dimensions, voltage rail, and flex connector pinout. One cell covers the full XA1 Ultra line without adapter or modification.
• Bench tested on actual hardware: We ran this cell on the XA1 Ultra mainboard and confirmed the BMS handshake completes correctly — the charge IC accepted the cell, reported state-of-charge without error flags, and the protection circuit tripped at the expected low-voltage cutoff threshold.
• Fuel gauge recalibration on first use: On first installation, disable fast charging and run one full discharge-to-charge cycle at standard current. This allows the fuel gauge IC to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the Xperia XA1 Ultra after a cell swap

The XA1 Ultra's Snapdragon 652 pulls significant current spikes when the modem switches bands or the 6-inch display hits peak brightness. A new cell with a slightly different internal resistance profile can hit the BMS low-voltage cutoff under that load even when the fuel gauge still reads 20–30%. The charge IC interprets the voltage sag as a critically low cell and cuts power immediately. Run one full uninterrupted discharge cycle — no charging mid-cycle — to let the coulomb counter recalibrate its endpoint voltage against the actual cell. After that cycle, unexpected shutoffs at mid-percentage typically stop.

USB fast charging not triggering after battery replacement

Sony's Quick Charge handshake on the XA1 Ultra requires the BMS to report a healthy cell state before the charge IC allows elevated current. On a freshly installed cell, the BMS may flag an uncalibrated state-of-charge, causing the charger to fall back to standard 5V/0.9A input. This is not a fault with the charger or the USB port. Charge the phone once at standard rate until it reaches 100%, then disconnect and allow one full discharge. After that cycle, reconnect the original Sony charger — the BMS will have a calibrated reference and fast charge should re-engage at the correct voltage.