Sennheiser ADAPT 230 Mono Replacement Battery 3.7V 180mAh

Sennheiser ADAPT 230 Mono / D10 / DW Office Series — 3.7V Li-Polymer Replacement Battery (504374 / BATT-03)

This 3.7V, 180mAh Li-Polymer cell replaces the original battery in the Sennheiser ADAPT 230 Mono, D10, DW Office, and DW Office ML wireless headsets. It restores power to the audio circuit and DECT radio module when the original cell has degraded. Dimensions are 37.00 × 17.70 × 4.77mm — a physical match for the original housing.

• ADAPT 230, D10, and DW Office platform compatibility: These models share the same 3.7V Li-Polymer cell format, connector pinout, and BMS handshake protocol — which is why one part number covers the full range. Swapping between these headsets does not require a different cell.
• Bench tested on actual hardware: We cycled this cell through the base station charge circuit and confirmed the BMS completed its handshake with the charging dock. The protection circuit responded correctly to end-of-charge and low-voltage cutoff thresholds.
• First charge protocol for DECT headsets: Place the headset in the base station and let it complete a full uninterrupted charge cycle before making any calls. DECT base stations log the new cell during this first cycle — skipping it causes inaccurate talk-time estimates and early cutoffs on the headset's power gauge.

Why the ADAPT 230 cuts out mid-call even with a new battery installed

The ADAPT 230 runs both the audio DSP and the DECT radio from the same 3.7V cell simultaneously. When the DECT radio transmits, current draw spikes sharply. If the new cell hasn't completed its first full charge cycle, available capacity sits at storage voltage — around 3.6V — and the BMS interprets the radio's draw spike as an undervoltage event and trips the protection circuit. The fix is a single full charge in the base station before first use. After that cycle, the BMS recalibrates its cutoff threshold to the cell's actual capacity.

Base station shows charging error after battery replacement

Sennheiser DECT base stations initiate a BMS handshake when a headset is docked — the base reads cell status before allowing charge current to flow. A new cell at storage voltage can return an out-of-range status code, causing the base to flag a fault rather than begin charging. Remove the headset, wait 10 seconds, and re-dock it firmly. If the error persists, check that the headset contacts are clean and making full contact with the dock pins — a partial connection at the dock will also prevent the handshake from completing.