Panasonic E6D20-AU78-1 Body Worn Mic Compatible Battery 3.7V

Panasonic Arbitrator Body Worn Mics — 3.7V Li-Polymer Replacement Battery (E6D20-AU78-1)

This is a 3.7V, 1600mAh Li-Polymer battery for the Panasonic Arbitrator Body Worn Microphone unit. It replaces OEM part number E6D20-AU78-1, which powers the body-worn recording hardware used in law enforcement and professional field audio work. Dimensions are 49.00 × 36.30 × 9.50mm — verify these against your existing cell before ordering.

• Arbitrator BWC microphone platform: The body-worn mic unit draws steady low-level current to keep the audio circuit and transmission link active. This cell matches the voltage rail and physical footprint the Arbitrator platform expects at the battery bay connector.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench, confirming the BMS accepted the cell without fault flags and that charge termination triggered correctly at full capacity.
• First-install charge cycle on body-worn units: Run one complete charge from flat to full inside the OEM docking station before deploying the unit. The Arbitrator charging cradle re-maps the fuel gauge to the new cell's discharge curve — skipping this step can cause the indicator to read inaccurately in the field.

Why the Arbitrator body-worn mic shows an incorrect charge level after battery swap

The Arbitrator unit tracks battery state using a voltage-threshold map calibrated to the original cell's discharge curve. A new Li-Polymer cell discharges at a slightly different curve, especially in the mid-range, so the indicator can read 20–30% off until the BMS recalibrates. Running one full charge cycle through the OEM docking cradle allows the system to re-anchor its thresholds to the new cell. After that cycle, the displayed percentage tracks accurately. If it still reads incorrectly after two cycles, check that the docking cradle contacts are clean and making firm contact.

Arbitrator mic unit powering off mid-shift despite showing partial charge

This usually means the BMS hit its low-voltage cutoff before the display caught up — common when a degraded cell was in service for an extended period and the gauge was miscalibrated to it. The replacement cell's BMS will cut output at 3.0V to protect the cell, but if the fuel gauge was mapped to an old degraded curve, it may still show 15–20% when cutoff triggers. One full charge-discharge cycle through the OEM cradle resets the reference point. After recalibration, the unit should reach cutoff and low-battery warning in the correct sequence.