Bose SoundLink Mini 2 Replacement Battery 7.4V 3400mAh

Bose SoundLink Mini 2 — 7.4V Li-ion Replacement Battery (088789)

This 7.4V, 3400mAh (25.16Wh) Li-ion cell replaces the original battery in the Bose SoundLink Mini 2 portable Bluetooth speaker. It fits the compact cylindrical housing and connects directly to the existing power management circuit. OEM part numbers 088789, 088796, 088772, and 080841 all cross-reference to this pack.

• SoundLink Mini 2 fit: The Mini 2 runs a single 7.4V Li-ion pack that feeds both the Class D amplifier and the Bluetooth radio. Both draws share the same cell, so a degraded pack affects audio output and wireless range at the same time — not as separate failures.
• Bench tested on actual hardware: We cycled this pack through the SoundLink Mini 2 charge circuit and confirmed the BMS handshake completed correctly. The protection board held cutoff at the expected low-voltage threshold and accepted charge from the original Bose 12V DC barrel charger without error codes.
• Fuel gauge calibration on the Mini 2: After fitting a new cell, run the speaker down to auto-shutoff at least once before recharging. The SoundLink Mini 2 fuel gauge calibrates its empty reference during that first full discharge — skipping it causes the indicator to read full while the cell is already under stress.

Why the SoundLink Mini 2 reads full charge but shuts off during playback

The Mini 2 fuel gauge is a coulomb counter — it tracks charge in and out rather than measuring cell voltage directly. If the battery has never been fully discharged, the counter loses its zero reference and starts reporting inflated percentages. A cell that is genuinely at 15% capacity can display 60% on the indicator. Once audio demand pulls current above what the weakened cell can sustain, the protection circuit trips and the speaker cuts off. Run a full discharge cycle to ground the counter and the indicator will track correctly from that point.

Audio distorting before the battery indicator reaches empty

At higher volume settings, the Class D amplifier in the Mini 2 draws current in short sharp spikes rather than a steady load. As the cell discharges below roughly 7.0V, internal resistance rises and those spikes cause voltage to sag momentarily. The amplifier interprets that sag as a supply fault and clips the output waveform — which is heard as distortion or a crackling sound, even though the battery indicator still shows charge remaining. Reducing volume while the speaker is in that low-voltage window stops the sag and clears the distortion immediately. After a full charge cycle on the new cell, voltage holds steady through the amplifier's demand peaks and the distortion does not return.