ZTE Blade V Smart Li3949T44P8h906450 3.85V Compatible Battery

ZTE Blade V Smart / Blade 20 Smart — 3.85V Li-Polymer Replacement Battery (Li3949T44P8h906450)

This is a 3.85V, 4900mAh (18.87Wh) Li-Polymer cell that replaces the original battery in the ZTE Blade V Smart, V1050, Blade 20 Smart, and Blade V2020 Smart. The OEM part number is Li3949T44P8h906450. If your phone shuts down unexpectedly, charges poorly, or won't hold power, this cell addresses a degraded or failed original unit.

• Blade V Smart and V2020 Smart series fitment: These models share a common battery bay geometry, connector pinout, and BMS handshake protocol. The Li3949T44P8h906450 cell is dimensioned at 86.70 × 62.75 × 5.00mm — any deviation causes housing pressure or connector misalignment, so confirm the OEM part number before ordering.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Blade V Smart platform. The BMS accepted the charge handshake without fault codes on the first cycle, and cell voltage held stable under sustained screen-on and modem load.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. The fuel gauge IC is calibrated to the old cell's discharge curve — letting it relearn against the new cell before high-current charging prevents percentage drift and premature low-battery warnings.

Sudden shutdown at 20–30% on the ZTE Blade V Smart after a cell swap

A new cell with an uncalibrated fuel gauge IC causes the phone to shut down well above 0% — typically between 15% and 30% reported charge. The coulomb counter still holds data from the old cell's voltage-capacity curve, so it misreads where the new cell's voltage cliff actually sits. Under modem transmit or screen-on load, the cell voltage drops faster than the IC predicts, and the phone cuts power to protect the circuit. Run one full discharge to automatic shutdown, then charge to 100% uninterrupted — after that cycle the IC maps the new cell and shutdowns at false percentages stop.

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

The ZTE charge IC negotiates fast-charge current with the BMS on the battery side before ramping voltage. On a freshly installed cell that hasn't completed a full cycle, the BMS can respond outside the expected timing window, causing the charge IC to fall back to standard 5V/1A input. This isn't a fault with the charger or the cable. Charge the phone once at standard rate to completion, then reconnect — the BMS sync completes correctly on subsequent cycles and fast charge activates at the correct voltage step.