Harman/Kardon Go Play Replacement Battery 7.4V 3000mAh

Harman/Kardon Go Play Series — 7.4V Li-Polymer Replacement Battery (CP-HK06)

This 7.4V, 3000mAh Li-Polymer battery replaces the original pack in the Harman/Kardon Go Play, Go Play Mini, and GO+ Play portable speakers. It matches the OEM part numbers CP-HK06 and GSP1029102 01. Swap it when the speaker no longer holds a charge or powers on after a full charge cycle.

• Go Play, Go Play Mini, and GO+ Play compatibility: All three models share the same battery bay dimensions, connector pinout, and BMS handshake protocol, which is why one pack covers the full lineup. The cell voltage and communication lines are identical across the series.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a Go Play unit, confirmed the BMS accepted the cell without error flags, and verified the fuel gauge reported correctly across the full state-of-charge range.
• Fuel gauge calibration tip: Let the speaker discharge below 20% at least once a month before recharging. Constant top-off charging without a full discharge cycle causes fuel gauge drift — the indicator reads full while actual capacity has fallen well below rated output.

Audio distorting before the battery indicator reaches empty

As cell voltage drops toward the lower end of the discharge curve, the amplifier stage in the Go Play can no longer sustain clean output at higher volume levels. The result is audible clipping or distortion even though the battery indicator still shows one or two bars. This happens because the fuel gauge triggers the low-battery warning at a voltage threshold, but amplifier headroom collapses earlier — especially on a degraded or partially discharged cell. If distortion starts consistently at mid-volume, check the resting cell voltage; it should read above 7.0V after a full charge.

Bluetooth dropping at high volume on a freshly charged pack

At peak playback volume, the amplifier and Bluetooth radio draw current simultaneously, creating a combined spike that can exceed what the BMS will sustain on a degraded cell. The BMS reads this as an over-current event and briefly disconnects the output rail, which drops the Bluetooth connection before it drops the audio. This is distinct from range-related dropout — it happens at close range with full signal. If the pack is new and the drop persists, confirm the cell is fully charged to 8.4V before testing at high volume.