Williams Sound BATAP97A WIRRX16 Replacement Battery 2.4V

Williams Sound WIRRX16 / WIRRX238 — 2.4V Ni-MH Replacement Battery (BATAP97A)

This is a 2.4V, 60mAh Ni-MH rechargeable cell for the Williams Sound WIRRX16 and WIRRX238 wireless receivers. These receivers are used in assistive listening systems to deliver audio wirelessly to listeners in the field. When the original cell can no longer hold a charge, this replacement restores the receiver to working condition.

• WIRRX16 and WIRRX238 compatibility: Both models run on the same 2.4V cell footprint with the same connector and physical dimensions (15 × 20 × 35mm), so one part number covers both receivers without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the WIRRX platform. The BMS accepted the pack without error, and the receiver held stable audio output across the full discharge curve without voltage sag triggering a shutoff.
• First-charge conditioning for assistive receivers: Place the receiver in its charging dock and let it complete one full uninterrupted charge cycle before use. The WIRRX base station reads cell state to calibrate the charge indicator — skipping this step causes the display to show inaccurate charge levels from the start.

Base station not recognising the new BATAP97A pack

The WIRRX charging base handshakes with the cell before it begins a charge cycle. A new Ni-MH pack at storage voltage can sit outside the window the base expects, so the dock shows no charging activity or flags an error. Seating the receiver firmly and waiting up to 90 seconds allows the base to detect the cell voltage and start the cycle. If the dock still shows no response, remove the receiver, wait 10 seconds, and reseat it — the base re-initiates the detection sweep each time contact is broken and restored.

Receiver cuts out mid-transmission on a freshly charged cell

The WIRRX16 draws simultaneously from the audio amplifier and the 2.4GHz radio, and that combined load can cause brief voltage sag on a cell that has not yet been through a full conditioning cycle. The BMS interprets the sag as a low-battery condition and cuts the output to protect the cell. This typically resolves after three to five full charge-discharge cycles, as the Ni-MH cell reaches its rated capacity. If cutouts persist beyond five cycles, check that the receiver contacts are clean and making solid contact with the cell terminals.