About this replacement
Xvive U6 Wireless Microphone Transmitter — 3.8V Li-Polymer Replacement Battery (502729)
This 3.8V, 260mAh Li-Polymer battery replaces the internal cell in the Xvive U6 Wireless Microphone Transmitter. The U6 is a compact wireless transmitter used in live sound, presentations, and studio recording setups. When the original cell degrades and the transmitter cuts out mid-use, this direct swap restores full operation.
- U6 transmitter fit: The U6 uses a small integrated Li-Polymer cell running at 3.8V to power both the DSP stage and the RF transmit circuit simultaneously. This cell matches that voltage rail, connector, and 26.00 × 23.20 × 4.00mm footprint exactly.
- Bench tested on actual hardware: We ran this cell under combined DSP and transmit load on the U6. The BMS held stable voltage across the full discharge curve without triggering an early cutoff under sustained RF output.
- Li-Polymer storage care for the U6: If the U6 will sit unused for more than two weeks, discharge to around 50% before storing. Li-Polymer cells stored at full charge accelerate electrolyte breakdown — a particular issue in a small 260mAh cell where degradation shows faster than in larger packs.
Why the U6 transmitter drops signal mid-performance on a new battery
The U6 draws current from two loads at once — the DSP processing block and the RF transmit stage. Under peak transmit load, current spikes briefly but sharply. If the replacement cell has a higher internal resistance than the original, voltage sags below the BMS cutoff threshold during those spikes. The transmitter interprets this as a depleted cell and shuts down even when the battery still holds charge. A properly spec'd 3.8V Li-Polymer cell with low internal resistance prevents the sag that triggers that false cutoff.
Battery indicator reads low immediately after fitting a replacement cell
The U6 battery indicator reads open-circuit voltage at power-on to estimate charge level. A replacement cell shipped in storage mode may sit at 3.5V or below, which the firmware maps directly to a low-battery state. This is not a fault with the cell. Charge the replacement fully before judging its state — a full charge cycle brings the cell to 4.2V and resets the indicator to full.