ZTE Axon 7 Li3931T44P8h756346 Replacement Battery 3100mAh

ZTE Axon 7 / Grand X4 — 3.85V Li-Polymer Replacement Battery (Li3931T44P8h756346)

This 3.85V, 3100mAh lithium-polymer cell replaces the original battery in the ZTE Axon 7, A2017U, A2017U Dual SIM LTE-A, and Grand X4 smartphones. It uses OEM part number Li3931T44P8h756346 and matches the original cell's dimensions at 74.10 × 62.80 × 4.30mm. Swap it in when the original no longer holds a usable charge or shuts down unexpectedly under load.

• Axon 7 and Grand X4 platform fit: Both the Axon 7 (A2017U) and Grand X4 share the same 3.85V cell footprint, connector pinout, and BMS handshake protocol — one part number covers the full family without hardware modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Axon 7 platform. The BMS accepted the cell, completed charge termination correctly, and the fuel gauge IC tracked state-of-charge without throwing calibration errors after a full conditioning cycle.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.

Sudden shutdown at 20–30% on the Axon 7 after a cell swap

This happens when the fuel gauge IC is still calibrated to the old cell's discharge curve. The new cell's actual voltage under modem and screen load drops below the cutoff threshold before the percentage reading reaches zero. The phone sees a voltage cliff — not a dead battery — and shuts down to protect the system. One full discharge-to-charge cycle at standard rate lets the coulomb counter reset against the new cell and eliminates the early cutoff.

USB-PD fast charge not triggering on the first cycle after replacement

The Axon 7's charge IC negotiates fast charge only after it confirms the cell's internal resistance and initial voltage are within an expected window. A brand-new cell at low state-of-charge can present higher impedance than the charge IC expects, causing it to fall back to standard 5V charging on that first session. This is a one-cycle behaviour — once the cell reaches full charge and the IC logs a complete cycle, fast charge negotiation resumes normally on subsequent plugs. If fast charge still does not trigger after two full cycles, check that the charger output voltage is confirmed at 9V under load.