ZTE Q505T Replacement Battery 3.8V 2000mAh LI3820T43P6H

ZTE Q505T / N9130 Speed — 3.8V Li-Polymer Replacement Battery (LI3820T43P6H903546-H)

This is a 3.8V, 2000mAh (7.6Wh) lithium-polymer cell that replaces the original battery in the ZTE Q505T, Speed (N9130), Vital, and related models. It matches OEM part numbers LI3820T43P6H903546-H, LI3720T43P6H903546, and LI3720T43P6H903546-H. The cell dimensions are 88.91 × 34.73 × 4.25mm — confirm these against your housing before installation.

• Q505T / N9130 platform fit: These models share the same battery bay dimensions, 3.8V nominal voltage rail, and connector pinout. One cell covers both because the BMS handshake and fuel gauge IC protocol are identical across the platform.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on compatible hardware. The BMS responded correctly to charge cutoff at 4.2V and discharged to the low-voltage protection threshold without tripping spurious cutoffs.
• Fuel gauge recalibration on first cycle: 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 its coulomb counter against the new cell's actual discharge curve before any high-current charge sessions begin.

Sudden shutdown at 20–30% on the ZTE Q505T after a cell swap

This is a voltage-cliff failure. The fuel gauge IC was calibrated to the old, degraded cell's internal resistance profile. When the modem radio or screen draws peak current from the new cell, the gauge reads available capacity incorrectly and triggers a low-voltage shutdown well above the actual depletion point. The fix is one full discharge-charge cycle with the phone in normal use — no fast charge, no top-up charging. After that cycle, the coulomb counter resets its baseline to the new cell and shutdowns at false percentages stop.

Phone reports wrong battery percentage after replacement

The percentage readout comes from the fuel gauge IC, not the cell itself. After a cell swap, the IC still holds the old cell's learned capacity and discharge curve in memory. This causes the percentage to jump erratically or drop suddenly — not because the cell is faulty, but because the gauge is comparing real-time voltage against the wrong reference. Run a full discharge down to auto-shutdown, then charge uninterrupted to 100% without removing the cable early. That single cycle gives the IC enough data to recalculate and stabilise the readout.