About this replacement
Sony S-Air Wireless Transceiver / EZW-RT10 — 3.7V Li-ion Replacement Battery (A1730971A)
This is a 3.7V, 1100mAh Li-ion replacement for the Sony S-Air Wireless Transceiver and EZW-RT10. It matches OEM part number A1730971A and fits the slim 54.05 × 34.10 × 5.40mm cell bay directly. The S-Air system uses this cell to power its wireless audio transmission link between compatible Sony audio devices.
- S-Air and EZW-RT10 fitment: Both models share the same 3.7V cell format, connector pinout, and BMS handshake protocol. A single cell SKU covers both units without modification.
- Bench tested on actual hardware: We cycled this cell through the S-Air transceiver's BMS under live audio transmission load. The protection circuit held cutoff at the correct low-voltage threshold and accepted charge without triggering fault flags.
- Fuel gauge reset after swap: After fitting this cell, run the transceiver until the battery indicator reaches empty, then charge uninterrupted to full. Skipping this step leaves the old fuel gauge calibration in place and the reported charge level will read inaccurately from the first use.
Capacity fade on the S-Air from constant top-off charging
The EZW-RT10 sits on a desk or shelf between uses, and most users top it off before it drops below 50%. Li-ion cells cycled repeatedly in the upper charge band — between roughly 70% and 100% — experience accelerated electrode stress compared to cells allowed to discharge further before recharging. Over months, this compresses usable capacity without any single obvious failure event. The cell reads "full" but delivers noticeably less before the low-battery indicator appears.
Audio distorting before the battery indicator reaches empty
This happens when a degraded or deeply discharged cell can no longer hold voltage steady under the combined draw of the RF transmitter and audio processing circuits. Voltage sags below the amplifier's stable operating range while the fuel gauge still shows remaining charge. The result is clipping or stuttering audio even though the unit hasn't shut down yet. Charge the new cell fully to 4.2V and run the fuel gauge reset cycle described above before drawing conclusions about the replacement cell's performance.