ZTE ZMAX Li3834T43P6h726452 Compatible Battery 3.8V 3400mAh

ZTE ZMAX Series — 3.8V Li-Polymer Replacement Battery (Li3834T43P6h726452)

This is a 3.8V, 3400mAh lithium-polymer replacement battery for the ZTE ZMAX smartphone and compatible models including the Q509T, Q509T Dual SIM TD-LTE, and Blade V2 Lite. It carries OEM part number Li3834T43P6h726452 and matches the original cell footprint at 70.85 × 63.50 × 5.00mm. If your ZMAX shuts down unexpectedly, no longer holds a charge, or won't power on, this cell replaces the degraded original.

• ZMAX and Q509T compatibility: These models share the same 3.8V nominal voltage rail, Li3834T43P6h726452 connector pinout, and BMS handshake protocol — which is why one cell covers the full variant lineup including the Dual SIM TD-LTE build.
• Bench tested on actual hardware: We cycled this cell through charge, load, and BMS cutoff sequences on compatible hardware. The protection circuit tripped correctly at the low-voltage threshold and accepted a full recharge without fault flags.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before the charge IC pushes higher current into an uncalibrated cell.

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

The ZMAX fuel gauge IC stores a discharge model calibrated to the original cell's internal resistance curve. A new cell has a different impedance profile, so the IC miscalculates the remaining capacity. Under modem or screen load, the voltage drops faster than the gauge predicts, and the phone hits the hardware cutoff before the percentage reaches zero. One full discharge-charge cycle at standard rate forces the coulomb counter to rebuild its model against the new cell, and the phantom shutdowns stop after that cycle completes.

USB fast charge not activating on the first cycle after replacement

On the first charge cycle with a new cell, the charge IC on the ZMAX may default to trickle or standard current rather than negotiating the fast charge protocol. This happens because the BMS presents a higher impedance state on a fresh, unformatted cell, and the charge IC reads that as an unsafe condition for high-current delivery. Let the first full charge complete at standard rate without interrupting it. Fast charge handshake typically resumes normally from the second cycle onward once the BMS has logged a clean completed cycle.