About this replacement
Bose SoundLink Mini — 7.4V Li-ion Replacement Battery (063404)
This is a 7.4V, 2600mAh Li-ion replacement battery for the Bose SoundLink Mini portable Bluetooth speaker (model 413295). It replaces OEM part numbers 063404 and 063287. When the original cell degrades and the speaker no longer holds a charge, this battery restores full operation.
- SoundLink Mini and 413295 compatibility: Both model variants share the same battery bay geometry, connector pinout, and BMS communication protocol. The same 7.4V cell architecture runs both, so one replacement covers the full Mini lineup without modification.
- Bench tested on actual hardware: We ran this battery in a SoundLink Mini chassis and confirmed the BMS handshake completed correctly on first connection — the speaker powered on, accepted a charge cycle, and the onboard fuel gauge reported state-of-charge accurately across the full discharge range.
- Fuel gauge reset on first install: After fitting this battery, run the speaker down to around 10% and then charge it uninterrupted to 100% before normal use. The SoundLink Mini's onboard fuel gauge needs one full cycle to calibrate against the new cell — skipping this step causes the charge indicator to read inaccurately from day one.
Capacity fade from constant desk-top charging on the SoundLink Mini
The SoundLink Mini is commonly left on its cradle or plugged in all day between uses. Li-ion cells kept at or near full charge experience elevated internal stress — high state-of-charge accelerates electrolyte oxidation at the cathode. Over months, this trims usable capacity without any single obvious failure event. Discharge the speaker below 20% at least once a month before recharging to slow this process on the replacement cell.
Audio distorting before the battery indicator reaches empty
As the cell voltage sags under amplifier load, the SoundLink Mini's amp stage loses its headroom before the fuel gauge trips the low-battery warning. The result is audible clipping and distortion at moderate-to-high volume while the indicator still shows one or two bars. This is a voltage-sag symptom, not a speaker fault. If distortion starts below 3.6V per cell (7.2V pack), the replacement cell is behaving normally — back the volume down slightly to reduce the current draw and the clipping will stop.