Logitech UE Boom NTA3083 Replacement Battery 3.7V 3400mAh

Logitech UE Boom / S-0012 — 3.7V Li-ion Replacement Battery (NTA3083)

This is a 3.7V, 3400mAh Li-ion replacement cell for the Logitech UE Boom portable Bluetooth speaker (model S-0012). It matches the OEM NTA3083 / 533-000105 spec and fits the cylindrical housing without modification. Swap it in when the original cell no longer holds a useful charge between sessions.

• UE Boom and S-0012 platform fit: Both the UE Boom and its S-0012 board variant share the same 3.7V single-cell architecture and NTA3083 connector pinout. The BMS handshake is identical across both, so the protection circuit communicates correctly with the charging IC on first boot.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the UE Boom board. The BMS engaged thermal protection as expected under sustained high-volume draw, and the charging IC accepted the cell without error flags on reconnection.
• Monthly discharge cycle for UE Boom: The UE Boom spends most of its life plugged in or topped off between short sessions. Let the speaker drain below 20% at least once a month before recharging — constant shallow cycling without a full discharge causes fuel gauge drift and accelerates cell capacity loss.

Capacity fade from desk-top charging on the UE Boom

The UE Boom is commonly used as a desk speaker and left on charge almost permanently. Li-ion cells held near 100% state of charge for extended periods experience elevated electrolyte oxidation at the cathode, which permanently reduces usable capacity. The cell doesn't fail suddenly — it degrades gradually until the gap between a "full" indicator and actual output is noticeable. Keeping the speaker between 20% and 80% during regular desk use slows this process significantly.

Audio distorting before the battery indicator reaches empty

This happens when the cell's internal resistance has risen enough to cause voltage sag under the amplifier's current draw — even though the fuel gauge still shows charge remaining. The amplifier clips because it's not receiving enough voltage, not because the audio signal is overdriven. The indicator lags because it reads state of charge, not instantaneous voltage under load. A fresh cell with lower internal resistance eliminates the sag; if distortion persists on a new cell, check that the battery connector is seated fully and reads at or above 3.6V under load.