ZTE N909 Li3818T43P3H605646 Replacement Battery 3.7V 1600mAh

ZTE N909 / V818 / U818 — 3.7V Li-ion Replacement Battery (Li3818T43P3H605646)

This is a 3.7V, 1600mAh Li-ion replacement cell for the ZTE N909, V818, and U818 smartphones. It replaces OEM part numbers Li3818T43P3H605646 and Li3715T42P3H605646. Swap it in when the original cell no longer holds charge or causes unexpected shutdowns.

• N909, V818, and U818 compatibility: These three ZTE models share the same battery footprint, connector pinout, and BMS handshake protocol — the same 3.7V cell services all three without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the ZTE platform, confirmed BMS communication, and verified the protection circuit trips correctly at both low-voltage cutoff and overcharge thresholds.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-to-charge cycle before normal use. The fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve — skipping this step causes the percentage readout to drift or jump erratically in the first few days.

Sudden shutdown at 20–30% on a freshly swapped cell

This happens because the fuel gauge IC was calibrated to the old cell's voltage-to-capacity curve. When the new cell's open-circuit voltage drops below what the OS expects at 20–30%, the phone reads it as critically low and cuts power. It is not a fault in the replacement cell. Run one complete discharge cycle — drain to automatic shutdown, then charge uninterrupted to 100% — and the coulomb counter resets against the actual cell curve. After that single cycle, the percentage readout stabilises.

Phone feels warm near the battery during the first few charges

A new cell arrives with slightly elevated internal impedance compared to a broken-in cell. The charge IC pushes current into a higher-resistance load during those first cycles, which produces more heat than you would see later. This is normal and settles after two to three full cycles as the cell's internal resistance drops. If the device stays warm past the third charge cycle, check that the back cover is seated correctly — trapped air between the cover and cell reduces heat dissipation.