Eartec ComStar CS-800LI Replacement Battery 3.7V 950mAh

Eartec ComStar Wireless Headsets — 3.7V Li-Polymer Replacement Battery (CS-800LI)

This 3.7V, 950mAh Li-Polymer cell replaces the original CS-800LI pack in Eartec ComStar wireless headset systems. The ComStar platform is used in aviation, construction, and live event environments where continuous, clear communication matters. Voltage and capacity match the original spec exactly.

• ComStar platform fit: The ComStar headset series shares a common 3.7V Li-Polymer cell format across units. The connector pinout, BMS handshake protocol, and physical dimensions — 43.00 × 35.80 × 13.00 mm — align with the OEM CS-800LI specification, so the base station recognises the new pack without reconfiguration.
• Bench tested on actual hardware: We cycled this cell through the ComStar base station charger and monitored BMS communication. The protection circuit responded correctly to full-charge cutoff and low-voltage lockout. No fault codes appeared during the charge sequence.
• First-cycle base station protocol: Seat the headset in the base station and run a complete charge cycle before taking your first call. The base station uses that initial cycle to log the new cell and calibrate the talk-time indicator — skipping it causes the display to report inaccurate charge levels for several sessions.

Base station showing a charging error after fitting a new pack

The ComStar base station communicates with the battery BMS during the first charge handshake to verify cell voltage and chemistry. If the replacement cell ships at storage voltage — typically around 3.6V — the base may flag a fault before the handshake completes. Remove the headset, wait 10 seconds, and re-seat it firmly in the charging cradle. If the fault clears, allow the full charge cycle to run uninterrupted to 4.2V before using the headset.

Headset cutting out mid-transmission on a fully charged new battery

The ComStar headset draws current on two simultaneous loads — the audio amplifier and the DECT radio transmitter. On the first few cycles of a new Li-Polymer cell, internal resistance is slightly elevated, and that combined draw can pull cell voltage below the BMS cutoff threshold momentarily, triggering a shutdown. This resolves progressively over three to five full charge-discharge cycles as the cell conditions. If cutouts persist past five cycles, check that the cell is reaching a full 4.2V charge before each use.