Logitech UE Boombox DGYF001 Replacement Battery 3.7V 2200mAh

Logitech UE Boombox — 3.7V Li-ion Replacement Battery (DGYF001)

This is a 3.7V 2200mAh Li-ion replacement battery for the Logitech UE Boombox portable Bluetooth speaker (model 984-000304). It replaces OEM part numbers DGYF001, GPRLO18SY002, and 533-000096. Fits the original battery bay with the same connector and cell footprint.

• UE Boombox compatibility: The 984-000304 Boombox runs a single-cell Li-ion pack at 3.7V nominal. The BMS in this unit monitors cell voltage directly and gates charging through the onboard charge controller — the replacement cell must match the OEM voltage window exactly or the controller rejects the charge cycle.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a UE Boombox unit, confirming BMS handshake, charge acceptance from the onboard controller, and stable voltage under combined amplifier and Bluetooth radio draw at high volume.
• Discharge cycling for the UE Boombox: Let the speaker discharge below 20% at least once a month before recharging. The UE Boombox is typically used as a desk or countertop speaker and constantly topped off from 60–80%. That shallow cycling causes fuel gauge drift on the onboard controller and accelerates capacity fade in the cell.

Bluetooth dropping at high volume on the UE Boombox

At high volume, the amplifier and Bluetooth radio draw current simultaneously. On a degraded cell, this combined spike causes momentary voltage sag below the radio's operating threshold. The Bluetooth stack drops the connection to protect the radio circuit, even though the battery indicator still shows charge. A fresh cell with lower internal resistance handles the combined draw without sagging — this is the primary reason Bluetooth dropouts appear only at loud playback levels and not at moderate volume.

Audio distorting before the battery indicator reaches empty

As a Li-ion cell ages, its internal resistance rises. Under amplifier load, the actual cell voltage drops faster than the fuel gauge reports — the indicator may show 30% while the delivered voltage is already too low for clean amplification. The amplifier clips at that reduced voltage, producing audible distortion before the low-battery warning fires. Replacing the cell restores the voltage headroom the amplifier needs; after replacement, charge fully to 4.2V before the first playback session to give the fuel gauge an accurate reference point.