About this replacement
Logitech UE Boom / S-0012 — 3.7V Li-ion Replacement Battery (NTA3083)
This is a 3.7V, 2600mAh Li-ion cell replacing OEM part NTA3083 in the Logitech UE Boom portable Bluetooth speaker (model S-0012). It fits the cylindrical battery bay and connects to the speaker's onboard charging and protection circuit. Capacity matches the original 9.62Wh rating from the factory spec.
- UE Boom and S-0012 compatibility: Both model names refer to the same first-generation cylindrical UE Boom hardware. The PCB, connector pinout, and BMS handshake are identical across the run, so a single cell covers both designations without modification.
- Bench tested on actual hardware: We cycled this cell through the UE Boom charge circuit and confirmed the BMS accepted the pack without fault codes. Charge termination triggered correctly at 4.2V, and the protection circuit held cutoff at the low-voltage threshold without tripping prematurely under speaker load.
- Fuel gauge reset after installation: The UE Boom's onboard fuel gauge can carry drift from the old cell. After fitting this battery, run the speaker down until it shuts off automatically, then charge uninterrupted to full. This recalibrates the gauge so the LED indicator reflects actual remaining capacity.
Capacity fade from constant top-off charging on the UE Boom
Most UE Boom owners leave the speaker on the USB charger between uses, topping it off before it drops below 50%. Li-ion cells stressed by shallow cycling develop a narrowing usable voltage window over time — the cell accepts charge but releases less of it under load. The fuel gauge reads full while actual deliverable capacity has quietly dropped. One full discharge-to-shutoff cycle per month gives the cell a chance to sweep its full voltage range and slows this degradation.
Audio distorting before the battery indicator reaches empty
The UE Boom's amplifier draws a sharp current spike at high volume, which causes a momentary voltage sag on a cell that's already in the lower part of its discharge curve — typically below 3.6V. That sag pushes the amplifier into clipping before the protection circuit reaches its low-voltage cutoff, so the speaker distorts while the LED still shows one bar remaining. The fix is to lower playback volume when the indicator hits the last bar, which reduces amplifier draw enough to keep rail voltage above the clipping threshold. If distortion starts earlier than expected on a new cell, recalibrate the gauge with one full discharge cycle first.