About this replacement
Harman/Kardon Onyx / JN14BKH00468 — 11.1V Li-Polymer Replacement Battery (PR-633496)
This is an 11.1V, 2500mAh (27.75Wh) Li-Polymer replacement battery for the Harman/Kardon JN14BKH00468, Onyx, and TL150409 portable speakers. It restores wireless playback on units where the original cell has degraded or failed entirely. Voltage and capacity match the original pack specification.
- Onyx series compatibility: The JN14BKH00468, Onyx, and TL150409 share the same 11.1V three-cell Li-Polymer architecture, connector pinout, and BMS handshake protocol — all three accept this pack without modification.
- Bench tested on actual hardware: We cycled this battery through charge and discharge on the Onyx platform. The BMS accepted the cell, balanced across all three groups, and held the protection thresholds at the expected cutoff points under both idle and active audio load.
- Monthly discharge cycle for Onyx users: The Onyx is frequently left on a desk or shelf topped off continuously. Run the speaker down below 20% at least once a month before recharging — constant shallow top-off without a full discharge causes fuel gauge drift and accelerates capacity fade on the Li-Polymer cell.
Audio distorting before the battery indicator reaches empty
As cell voltage sags under combined amplifier and radio draw, the amp hits its minimum supply rail before the battery gauge reads zero. The result is audible clipping or distortion at moderate-to-high volume even though the display still shows charge remaining. A degraded or partially charged cell has higher internal resistance, which makes the voltage drop sharper under load. If the distortion clears when you lower volume or plug in AC power, the cell — not the amplifier — is the cause.
Speaker won't wake from USB-C after sitting unused for weeks
Li-Polymer cells left uncharged for extended periods can self-discharge below the USB-C PD minimum acceptance voltage, typically around 2.5V per cell. At that point the BMS blocks incoming charge as a protection measure and the speaker shows no response on the USB-C port. Apply a 5V supply via the DC barrel input if the unit has one, or use a Li-Po trickle charger directly on the pack at 0.1C until cell voltage recovers above 3.0V per cell — then connect USB-C to resume normal charging.