Listen Technologies LA-365 M1 Replacement Battery 3.7V 1050mAh

Listen Technologies M1 / iDSP Receivers — 3.7V Li-ion Replacement Battery (LA-365)

This is a 3.7V, 1050mAh Li-ion cell built to the LA-365 spec. It fits the Listen Technologies M1 wireless headset, iDSP receivers, Point M1 Microphone, and Media Interface units. The battery slots into the same compartment as the original and connects through the same BMS interface.

• M1 and iDSP receiver compatibility: These devices share the same 3.7V rail, physical footprint, and connector pinout. The LA-365 cell works across the family because the BMS communication protocol is identical — no firmware differences between models affect charging handshake.
• Bench tested on actual hardware: We ran this cell through charge cycles on M1 hardware and monitored the BMS handshake at the base station. The protection circuit tripped correctly at low-voltage cutoff and accepted a full charge cycle without error flags.
• First-cycle base station logging: Seat the headset in the base station and let it complete a full uninterrupted charge before use. The base needs that first cycle to log the new cell — until it does, the talk-time estimate displayed may read inaccurately low.

Why the M1 cuts out mid-transmission on a freshly charged battery

The M1 draws from two simultaneous loads — audio decoding and the DECT radio transmitter. Under that combined draw, a cell sitting at storage voltage can sag below the BMS cutoff threshold even though it showed a full charge indicator. This happens most often on the first one or two cycles after fitting a replacement cell. Three to five full charge-discharge cycles allow the cell chemistry to stabilise and voltage sag to reduce. If cutouts persist past cycle five, check that the base station contact pins are clean and making full contact.

Base station shows a charging error after fitting the LA-365

A charging error on the base display usually means the BMS handshake did not complete — the base polled the cell before the protection circuit had initialised. Remove the headset from the base, wait 10 seconds, then reseat it firmly. If the error persists, inspect the three contact points inside the headset battery bay for oxidation or debris. Clean contacts with a dry cotton swab and reseat again — the handshake should complete within 30 seconds of correct seating.