About this replacement
Bose SoundLink / SoundTouch 20 — 11.1V Li-ion Replacement Battery (330107)
This 11.1V, 2200mAh Li-ion battery replaces the original pack in the Bose SoundLink, SoundLink 3, SoundTouch 20, and related models. It covers OEM part numbers 330107, 330107A, 359495, 359498, 330105, 330105A, 404600, and 404900. Swap it in when the original cell no longer holds charge through a full listening session.
- SoundLink and SoundTouch 20 compatibility: These models share the same 11.1V three-cell architecture, connector pinout, and BMS communication protocol — so one battery covers the full group without modification.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a SoundLink unit, confirmed the BMS handshake completed without fault codes, and verified the fuel gauge reported accurately across the full state-of-charge range.
- Fuel gauge reset after install: After fitting this battery, run it down to the low-battery warning before the first recharge. The SoundLink's fuel gauge calibrates on a full discharge-to-charge cycle — skipping this step causes the indicator to read full while the speaker cuts out early.
Capacity fade from constant desk-top charging on the SoundLink
The SoundLink is frequently left on its charger between uses — topped off before it drops below 60%. Li-ion cells cycled repeatedly in the upper voltage band lose active lithium faster than cells allowed to discharge more fully. Over months, the usable capacity shrinks while the fuel gauge still reads normal. Letting the pack drop below 20% at least once a month before recharging slows this degradation and keeps the gauge accurate.
Audio distorting before the battery indicator reaches empty
At high volume, the SoundLink amplifier pulls current spikes that cause the battery voltage to sag below the amp's clean-power threshold while the gauge still shows charge remaining. The result is audible clipping or distortion — not a speaker fault. This happens most on aged cells but can also occur on a new battery if the fuel gauge is uncalibrated. Run one full discharge cycle after installing this battery, and the gauge will align with actual cell voltage so the speaker behaves predictably at all volume levels.