Harman/Kardon Onyx Studio 1 Replacement Battery LI11B001F 3.7V

Harman/Kardon Onyx Studio 1 / Studio 2 — 3.7V Li-ion Replacement Battery (LI11B001F)

This is a 3.7V, 2600mAh Li-ion cell that replaces part number LI11B001F in the Harman/Kardon Onyx Studio 1 and Onyx Studio 2 portable Bluetooth speakers. It sits inside the speaker chassis and powers both the amplifier board and the Bluetooth radio simultaneously. Capacity figure is 2600mAh (9.62Wh) — matched to the original spec.

• Studio 1 and Studio 2 compatibility: Both models use the same LI11B001F cell with identical voltage rail, physical footprint (68.25 × 18.60 × 18.60mm), and connector orientation. The BMS on both units reads the same protection thresholds, so one cell covers both generations without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Onyx Studio platform and confirmed the BMS accepted the pack without a protection trip. Over-voltage cutoff and discharge cutoff both triggered at expected thresholds with no cell rejection errors.
• Fuel gauge reset after swap: After fitting a new cell, run the speaker until it shuts off from low voltage, then charge it uninterrupted to 100%. The Onyx Studio fuel gauge recalibrates on that first full cycle — skipping it causes the indicator to misread remaining charge from day one.

Capacity fade from constant top-off charging on the Onyx Studio

The Onyx Studio is commonly left on a charger at a desk or shelf, which means the cell spends most of its life sitting at or near 100%. Li-ion cells held at high state of charge accelerate electrolyte oxidation at the cathode — this is not a fault, it is a chemistry characteristic. Over months, usable capacity drops noticeably even though the speaker appears to charge normally. Discharge the cell to below 20% at least once a month before recharging to slow this process down.

Audio distorting before the battery indicator reaches empty

When the cell ages, its internal resistance rises. Under the combined current draw of the amplifier and Bluetooth radio at high volume, voltage sags below what the amp needs to swing clean output — even if the indicator still shows charge remaining. The result is clipping and distortion that sounds like a speaker fault but clears the moment volume drops. If distortion starts appearing at medium-to-high volume with 20–30% charge showing, the cell's internal resistance has risen too far. Replacing the cell restores the voltage headroom the amplifier needs.