Xvive U6 Wireless Microphone Receiver Replacement Battery 3.7V 420mAh

Xvive U6 Wireless Microphone Receiver — 3.7V Li-Polymer Replacement Battery (AHB452730)

This 3.7V 420mAh Li-Polymer cell replaces the AHB452730 battery in the Xvive U6 Wireless Microphone Receiver. The U6 receiver sits in the signal chain between the transmitter and your audio source — when this cell degrades, the receiver loses hold on the RF link before any low-battery LED fires. At 30.30 x 25.30 x 4.50mm it fits the original battery bay with no modification.

• U6 receiver fitment: The AHB452730 cell is specific to the U6 receiver unit — not interchangeable with the transmitter pack. The connector polarity and BMS communication line are matched to the receiver's onboard charge circuit, which runs a different charge profile than the transmitter side.
• Bench tested on actual hardware: We ran the U6 receiver through full RF acquisition and sustained audio pass-through. The BMS held the 3.7V nominal rail steady under combined DSP and RF receive draw, and the protection circuit triggered cleanly at the low-voltage cutoff threshold without nuisance trips.
• Receiver storage between gigs: The U6 receiver's BMS will enter deep-discharge protection if stored at full depletion for more than two weeks. Store the receiver at roughly 50% charge — enough cell voltage to keep the BMS active so it accepts a charge immediately next session.

Why the U6 receiver drops the RF link mid-performance on a new battery

A fresh Li-Polymer cell at 4.2V full charge can cause a brief voltage fluctuation when the receiver's RF front-end and DSP draw current simultaneously at power-on. If the cell's internal resistance is slightly elevated — common in cells that sat in warehouse inventory — the voltage briefly sags below the BMS trip threshold, and the receiver resets the RF link. The fix is to cycle the new battery once through a full charge before the first live use. This conditions the cell's internal resistance and stabilises the voltage rail under combined load.

Receiver won't re-sync with transmitter after swapping the battery

Replacing the receiver battery cuts power to the RF pairing memory on some U6 firmware versions — the receiver wakes up without the transmitter's channel stored. This is not a battery fault; it is a power-loss re-initialisation. After fitting the new cell, hold the pairing button on both the transmitter and receiver until the sync LED confirms lock. Confirm the transmitter is sending signal at its set frequency before assuming the battery is the fault.