Sonumaxx 2.4 Range Replacement Battery 3.7V 350mAh

Sonumaxx 2.4 Range / 2.4 PR Receiver — 3.7V Li-Polymer Replacement Battery (230-469)

This 3.7V, 350mAh lithium-polymer cell replaces the original battery in the Sonumaxx 2.4 Range and 2.4 PR Receiver wireless headsets. It matches the OEM part number 230-469 and restores wireless audio and DECT transmission functions. Dimensions are 35.00 × 30.44 × 15.18mm — confirm against your existing cell before fitting.

• 2.4 Range and 2.4 PR Receiver compatibility: Both models run the same 3.7V cell with an identical connector and BMS handshake profile. One cell covers the full platform — no hardware differences affect fitment between these two variants.
• Bench tested on actual hardware: We ran this cell through charge cycling on a 2.4 Range headset base station. The BMS completed handshake correctly, accepted charge without error flags, and held voltage within expected tolerance under combined audio and DECT radio draw.
• First charge in the base station: Seat the headset in its base and let it complete one full charge cycle before use. DECT headsets log the new cell during this cycle — skipping it means the talk-time indicator will read inaccurately until the base recalibrates.

Voltage sag under combined audio and DECT radio draw

The 2.4 Range headset runs audio processing and a 2.4GHz radio transmitter simultaneously from a single 350mAh cell. That combined draw creates brief current spikes — most pronounced during voice activity peaks. A worn cell with elevated internal resistance drops voltage sharply during those spikes, which the BMS reads as a low-battery event even if the indicator shows charge remaining. A fresh cell at proper capacity handles the spike without tripping the cutoff.

Base station showing full charge but headset cuts off after a short call

This happens when a new cell arrives at storage voltage — typically 3.6–3.7V — and the base stops charging before delivering a true full cycle. The indicator reads 100% but usable capacity is much lower. Place the headset back in the base for a complete uninterrupted charge, then remove and re-seat it once. The base should then log the correct cell state and charge to a genuine full voltage of around 4.2V.