Bose SoundLink Mini 063404 Replacement Battery 7.4V 3400mAh

Bose Soundlink Mini — 7.4V Li-ion Replacement Battery (063404)

This 7.4V, 3400mAh Li-ion battery replaces part numbers 063404 and 063287 in the Bose Soundlink Mini portable Bluetooth speaker (model 413295). It fits the compact housing directly and reconnects to the same BMS contacts as the original cell. Use this when the existing pack no longer holds a full charge or fails to power the speaker at all.

• Soundlink Mini and 413295 compatibility: Both the Soundlink Mini and model 413295 share the same 7.4V two-cell Li-ion configuration, connector pinout, and BMS handshake protocol — one battery covers both.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a Soundlink Mini unit. The BMS accepted the cell without error, balanced both cells correctly, and the speaker reported charge state accurately on the LED indicator.
• Fuel gauge reset after install: After fitting this battery, run the speaker down until it shuts off automatically, then charge it uninterrupted to 100%. Skipping this step leaves the fuel gauge calibrated to the old degraded cell, so the charge indicator will read inaccurately from day one.

Capacity fade from constant top-off charging on the Soundlink Mini

The Soundlink Mini is typically left on a desk as a desktop speaker and plugged in whenever it drops below 80%. That shallow cycling pattern — never going below 50% before recharging — causes the Li-ion cells to lose capacity faster than normal discharge cycles would. The BMS also loses calibration reference points because it never sees a full low-end voltage. Discharge below 20% at least once a month before a full charge to slow this degradation and keep the fuel gauge accurate.

Audio distorting before the battery indicator reaches empty

The Soundlink Mini's amplifier draws a sharp current spike at high volume. When the battery cell voltage sags under that combined amplifier and Bluetooth radio load, the amp clips before the battery indicator has dropped to the low warning level. This makes the speaker sound like it is distorting from a software issue when it is actually a voltage sag problem at the cell level. If distortion appears at medium-to-high volume on a battery reading above 30%, the cell can no longer hold its voltage under load — check cell voltage under load; a healthy pack should not drop below 6.8V during playback.