AKG N90Q Replacement Battery 3.7V 1200mAh P803050

AKG N90Q — 3.7V Li-Polymer Replacement Battery (P803050)

This 3.7V, 1200mAh Li-Polymer battery replaces the internal cell in the AKG N90Q wireless noise-cancelling headset. It fits directly into the N90Q housing and matches the original P803050 specification. Capacity is sourced from the product data at 1200mAh (4.44Wh) — do not substitute a higher-capacity cell without verifying fit dimensions against the 49.00 × 30.00 × 7.20mm footprint.

• N90Q platform fit: The N90Q runs adaptive noise cancellation and DECT radio simultaneously from a single cell. Both draws share the same voltage rail, so the BMS must handle combined current spikes without false low-voltage trips. This cell's protection circuit is rated to that dual-load profile.
• Bench tested on actual hardware: We cycled this cell through full charge and load discharge on the N90Q platform. The BMS held cutoff voltage correctly, the noise-cancellation circuit remained active under sustained draw, and no thermal anomalies appeared during the charge phase.
• First-charge protocol for the N90Q: Seat the headset in its charging cradle and run one complete charge cycle before use. The N90Q's talk-time estimator reads cell state from the base station — it will not display an accurate charge level until the BMS and base have completed their first full handshake cycle.

Why the N90Q cuts out mid-call on a new battery

The N90Q draws current from two active systems at once — the audio processor and the DECT radio. During a call, that combined draw creates short current spikes that a partially initialised BMS can misread as a low-voltage event. The protection circuit then trips and drops the headset off the call. This is not a fault in the cell. Running two or three full charge cycles through the base station conditions the BMS to the N90Q's actual load signature and the cutouts stop.

Base station showing full charge but headset dies after short use

A replacement Li-Polymer cell ships at storage voltage — typically around 3.6V — not at full charge. The N90Q base station can read this as a charged state before the cell has actually been topped up. The result is a headset that appears ready but cuts off quickly under load. Fix it by placing the headset in the cradle for a full uninterrupted charge cycle. After that cycle, the base station's charge indicator reflects the actual cell state.