Verizon 10 Replacement Battery 3.85V 3850mAh Li-Polymer

Verizon 10 / 10A++ — 3.85V Li-Polymer Replacement Battery

This 3.85V, 3850mAh Li-Polymer battery replaces the original cell in the Verizon 10 and 10A++ smartphones. It fits the stock battery bay with no modification to the housing or connector. Rated at 14.82Wh, it matches the original cell's voltage rail exactly.

• Verizon 10 and 10A++ compatibility: Both models share the same battery bay dimensions (83.10 × 62.68 × 4.30mm), voltage rail at 3.85V nominal, and connector pinout — so a single cell covers both variants without any wiring change or BMS re-mapping.
• Bench tested on actual hardware: We cycled this cell through charge, idle draw, and screen-on load. The BMS responded correctly to charge termination, held cutoff voltage under sustained modem load, and reported state-of-charge to the fuel gauge IC without erratic jumps after a full calibration cycle.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging and run one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate its coulomb counter against the new cell's discharge curve before high-current charging is applied to an uncalibrated cell.

Sudden shutdown at 20–30% on the Verizon 10 after a cell swap

A new Li-Polymer cell has a slightly different voltage-versus-capacity curve than the aged cell the fuel gauge IC was trained on. When the phone hits a load spike — LTE handoff, screen brightness jump — the cell voltage drops sharply at around 3.6–3.7V, and the IC reads that as a critical low-battery event. The phone shuts down even though the coulomb counter still shows charge remaining. One full discharge-to-cutoff and charge-to-100% cycle resets the IC's internal model to the new cell, and the early shutdowns stop.

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

On the first charge after a battery swap, the charge IC may default to a slow trickle rate while it confirms the new cell's BMS handshake. This is normal — the phone is verifying that the BMS accepts the fast-charge voltage contract before pushing higher current. If fast charge does not activate after the first full cycle, check that the charger output is at least 18W and the cable supports USB-PD signalling. If the issue persists past the second cycle, test with the original Verizon wall adapter at 9V/2A to confirm the port and cable are not the limiting factor.