Sony Xperia XZ1 LIP1645ERPC Replacement Battery 3.85V 2600mAh

Sony Xperia XZ1 / G8342 — 3.85V Li-Polymer Replacement Battery (LIP1645ERPC)

This is a 3.85V, 2600mAh Li-Polymer cell replacing the original LIP1645ERPC in the Sony Xperia XZ1 series. It fits the XZ1, XZ1 TD-LTE, G8342, and G8343 variants. Swap it in when the original cell no longer holds enough charge to get through a normal day.

• XZ1 and G8342/G8343 platform fit: These models share the same battery bay geometry, connector pinout, and BMS handshake. The LIP1645ERPC form factor — 102.50 × 42.25 × 4.15mm — is consistent across all listed variants, so one cell covers the full range without modification.
• Bench tested on actual hardware: We ran this cell through a full charge and discharge cycle on the XZ1. The BMS accepted the new cell without fault flags, charge current stepped down correctly at 4.35V, and the protection circuit tripped cleanly at the low-voltage cutoff threshold.
• First-cycle fuel gauge reset: After installation, turn off fast charging in the battery settings and run one complete discharge-charge cycle at standard current. This gives the fuel gauge IC time to map the new cell's discharge curve before fast charging pushes higher current into an uncalibrated cell.

Sudden shutdown at 20–30% on the Xperia XZ1 after a cell swap

This happens because the fuel gauge IC is still running a discharge model calibrated to the old, degraded cell. The new cell has a steeper voltage drop under modem and screen load than the IC expects, so it cuts power before the percentage reaches zero. The fix is a full calibration cycle: drain to auto-shutdown, then charge uninterrupted to 100% without using the phone. After one or two of these cycles, the coulomb counter realigns with the new cell's actual voltage cliff.

USB fast charging not activating on the first cycle after replacement

On the first charge after a cell swap, the XZ1's charge IC may refuse to negotiate fast charge because the BMS has not yet confirmed cell health to the system. The phone defaults to standard 5V/1A to protect an uncalibrated cell. Charge fully once at standard rate, disconnect, then reconnect — the handshake typically completes on the second session and fast charge resumes. If it does not, check that the charger outputs at least 9V/1.67A and the cable supports USB-PD signalling.