Interphone ACTIVE Wireless Headset Compatible Battery 3.7V 800mAh

Interphone ACTIVE / CONNECT / EDGE / F2 Series — 3.7V Li-Polymer Replacement Battery

This 3.7V, 800mAh Li-Polymer cell replaces the original battery in the Interphone ACTIVE, CONNECT, EDGE, and F2 wireless Bluetooth headsets, along with 15 additional compatible models in the same family. It restores full audio and radio function to headsets where the original cell has degraded or failed. Capacity is 2.96Wh — matched to the original specification.

• ACTIVE / CONNECT / EDGE / F2 shared platform: These models run on the same 3.7V single-cell architecture with a common connector and BMS handshake protocol. Swapping cells across this family works because the protection circuit board interface and physical footprint — 52 × 20 × 8mm — are consistent throughout the lineup.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the ACTIVE platform. The BMS accepted the pack without fault codes, protection thresholds triggered correctly at both ends of the voltage range, and audio output held stable under combined Bluetooth radio and speaker draw.
• First-cycle base station protocol: Seat the headset in the base station and let it complete one uninterrupted full charge before making any calls. The base logs the new cell's capacity signature during this cycle — skipping it causes the talk-time indicator to read inaccurately for the first week of use.

Why the ACTIVE cuts out mid-call on a degraded cell

The ACTIVE draws current from two loads simultaneously during a call: the Bluetooth radio and the speaker driver. On a degraded cell, internal resistance rises enough that this combined draw pulls the terminal voltage below the BMS cutoff threshold — typically around 3.0V — even when the gauge still shows charge remaining. The headset shuts down not because the cell is empty, but because it can no longer sustain the voltage under load. Replacing the cell resets internal resistance to factory levels and eliminates this mid-call dropout pattern.

Base station shows full charge but headset cuts off after a few minutes

A new cell ships at storage voltage — typically 3.6–3.8V — not at full charge. If the base station reads this as "charged" and stops the charge cycle early, the headset enters service with far less capacity than rated. The fix is to force a full charge cycle: remove the headset, reinsert it, and confirm the charge indicator is actively cycling rather than showing static full. Allow the charge to complete fully before use — the cell needs to reach at least 4.1V before the first call.