Sprint Fury Li-ion Replacement Battery 3.7V 1500mAh

Sprint Fury — 3.7V Li-ion Replacement Battery (Li3715T42P3h415266)

This is a 3.7V, 1500mAh Li-ion cell that replaces the original battery in the Sprint Fury smartphone. It fits the Fury's battery bay directly, restoring power to calls, messaging, and apps when the stock cell no longer holds charge. Capacity figure is 1500mAh as spec'd — matching the OEM rating.

• Sprint Fury compatibility: The Fury uses a single-cell Li-ion pack at 3.7V nominal with a fixed connector and BMS handshake tied to part number Li3715T42P3h415266. This cell matches that voltage rail and connector pinout — the BMS accepts it without triggering a fault state at power-on.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on the Fury platform. The BMS accepted the cell without entering protection mode, and charge termination triggered correctly at 4.2V. Voltage held stable under screen-on and cellular radio load throughout the test.
• Fuel gauge recalibration on first use: On first installation, disable fast charging and run one complete discharge-to-charge cycle before enabling it again. This gives the Fury's fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.

Why the Fury reports wrong battery percentage after a cell swap

The Fury's fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual cell chemistry and impedance. The OS reads from the old model, so percentage readouts drift — often showing full charge when the cell is mid-range. One complete discharge below 5% followed by a full uninterrupted charge resets the coulomb counter and lets the IC build a fresh curve against the new cell.

Sudden shutdown at 20–30% remaining on the replacement cell

This happens when the fuel gauge IC is still calibrated to the old cell and the Fury hits a voltage cliff the OS did not anticipate. Under modem or display load, cell voltage drops faster than the uncalibrated gauge predicts — the phone cuts power before the reported percentage reaches zero. It is not a faulty cell. Run one full discharge cycle without interruption, then charge to 100% without removing the phone from the charger, and the shutdowns will stop once the gauge IC has a new reference point.