Verizon UV-X4 Replacement Battery 3.7V 1050mAh Li-ion

Verizon UV-X4 — 3.7V Li-ion Replacement Battery

This 3.7V, 1050mAh lithium-ion battery is a direct swap for the Verizon UV-X4 handheld two-way radio. It matches the original pack's voltage rail and physical footprint at 53.20 x 35.30 x 7.10mm. No OEM part number was issued for this pack; fit is confirmed against the UV-X4 model only.

• UV-X4 platform fit: The UV-X4 runs a single-cell 3.7V Li-ion architecture. This battery matches that voltage rail and uses a connector profile sized to the UV-X4 chassis. The BMS is tuned to the transmit current draw profile of compact handheld transceivers in this power class.
• Bench tested on actual hardware: We cycled this pack through transmit loads representative of sustained PTT use. The BMS held cutoff thresholds steady across multiple discharge cycles, with no premature overcurrent trips during the high-current spike at PTT press.
• First insertion contact check: If the charger dock shows a fault LED on the first insertion, remove the battery, wipe the contact pads with a dry cloth, and reseat firmly. The UV-X4 dock requires a clean contact cycle to complete the BMS handshake before charging begins.

UV-X4 cutting out mid-transmission on a new battery

A new Li-ion cell ships at storage voltage — typically around 3.6–3.75V — not at a full charge state. When PTT is pressed, transmit current spikes sharply. If the cell hasn't completed at least one full charge cycle, the BMS may interpret that spike as an overcurrent event and trip the protection circuit. The radio cuts out, and the user assumes the battery is faulty. Run the battery through one complete charge before first use on air. After a full charge cycle, the BMS has a calibrated baseline and handles the PTT spike without tripping.

Bar indicator showing fewer bars than expected after inserting a new pack

The UV-X4 uses a simple voltage-threshold bar indicator — it reads resting cell voltage and maps it to bar segments. A new battery at storage voltage (roughly 3.6–3.7V) will show one or two bars, not four. This is not a fault with the cell. Place the battery on charge until the dock shows a full-charge indicator, then reinsert. The bar display will reflect the actual charged voltage — typically at or above 4.1V — and show correctly.