Harman/Kardon Allure Portable Compatible Battery 3.7V 6000mAh

Harman/Kardon Allure Portable — 3.7V Li-Polymer Replacement Battery (GSP872693 03A)

This is a 3.7V 6000mAh Li-Polymer battery for the Harman/Kardon Allure Portable Bluetooth speaker. It replaces part number GSP872693 03A — the original cell that sits inside the fabric-wrapped portable enclosure. Capacity is rated at 22.2Wh, matching the factory specification.

• Allure Portable fitment: The Allure Portable uses a flat Li-Polymer pouch cell with a proprietary connector and a BMS that reports state-of-charge to the speaker's fuel gauge IC. Physical dimensions are 93.80 × 32.00 × 19.80mm — the housing leaves no slack, so cell geometry has to match exactly.
• Bench tested on actual hardware: We cycled this cell through the Allure Portable's charge and discharge circuit. The BMS handshake completed on first connection, the fuel gauge calibrated correctly, and the amplifier stage drew cleanly across low, medium, and high volume levels without triggering low-voltage cutoff.
• Fuel gauge reset for the Allure Portable: If the speaker reports inaccurate charge levels after fitting a new cell, run one full discharge to the auto-shutoff point before recharging to 100%. This recalibrates the fuel gauge IC. Skipping this step on the first cycle causes the indicator to drift and the speaker to cut out earlier than the actual cell capacity warrants.

Why the Allure Portable cuts out at high volume even on a full charge

The Allure Portable's Class D amplifier pulls a sharp current spike when audio peaks hit maximum output. An aged or degraded cell has higher internal resistance, so voltage sags under that spike even when the fuel gauge still reads full. The BMS interprets the sag as a low-voltage event and triggers a protective cutoff. A fresh cell with low internal resistance handles the transient load without the voltage drop, keeping the BMS from tripping mid-track.

Speaker warm to the touch and charge draining faster than expected during extended sessions

The Allure Portable's fabric housing traps heat from two sources simultaneously — the discharge heat from the Li-Polymer cell and the waste heat from the amplifier board. Elevated operating temperature accelerates capacity fade in Li-Polymer cells and temporarily reduces available capacity per session. If the outer surface feels noticeably warm during playback, reduce volume or move the speaker to a surface with better airflow. After the session, let the unit cool to room temperature before placing it back on charge — charging a warm Li-Polymer cell compresses usable cycle life faster than normal use alone.