BTR6425B Verizon Rezound Compatible Battery 3.7V 1150mAh

Verizon Rezound ADR6425 — 3.7V Li-ion Replacement Battery (BTR6425B)

This is a 3.7V, 1150mAh Li-ion cell that replaces the original battery in the HTC Rezound (ADR6425, ADR6425LVW) sold on Verizon's network. It fits the standard battery bay and connects via the same three-contact connector as the OEM unit. Replacement part numbers BTR6425, 35H00168-02M, and 35H00168-03M all cross-reference to this same cell.

• ADR6425 and ADR6425LVW compatibility: Both Rezound variants use the same 3.7V single-cell bay, identical connector pitch, and the same BMS handshake with the Qualcomm Snapdragon S3 power rail. One cell fits both.
• Bench tested on actual hardware: We cycled this cell in an ADR6425LVW unit and confirmed the BMS handshake completed on first boot — no low-battery loop, no false charge state on the status LED.
• Fuel gauge recalibration on first use: After installing this cell, run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% before using the phone normally. The Rezound's coulomb counter is calibrated to the old cell's discharge curve — skipping this step causes erratic percentage readings from day one.

Why the Rezound reports wrong battery percentage after a cell swap

The Rezound tracks charge state using a coulomb counter that was calibrated against the original cell's specific discharge curve. A new cell has a slightly different internal impedance profile, so the counter's stored reference no longer matches real voltage. The phone reads percentage from that stale reference and reports numbers that drift or jump. One full discharge-to-shutdown followed by a full uninterrupted charge resets the reference and brings the display back in line with actual charge state.

Sudden shutdown at 20–25% on the replacement cell

This happens when the LTE modem or display draws a current spike the cell cannot sustain at low state-of-charge — voltage drops below the BMS cutoff threshold even though the fuel gauge still shows charge remaining. It is a calibration gap, not a defective cell. Run the full recalibration cycle described above: drain to auto-shutdown, recharge to 100% without interruption. After one complete cycle the BMS and fuel gauge align, and the cutoff point drops back to the correct low-voltage floor near 3.2V.