Sony WH-1000XM2 Replacement Battery 3.7V 1050mAh Li-ion

Sony WH-1000XM2 / MDR-1ABT Series — 3.7V Li-ion Replacement Battery (4-296-914-01)

This is a 3.7V, 1050mAh Li-ion cell replacing OEM part 4-296-914-01. It fits the Sony WH-1000XM2 wireless noise-cancelling headphones along with the MDR-1ABT, MDR-1ADAC, and SRS-BTS50. Use capacity figures from this listing — 1050mAh — not third-party sources.

• WH-1000XM2 and MDR-1ABT platform: These headphones share a common 3.7V single-cell architecture with the same connector pinout and BMS handshake protocol. The noise-cancellation circuit and Bluetooth radio draw from the same cell, so cell capacity directly affects how long active noise cancellation stays on alongside audio playback.
• Bench tested on actual hardware: We ran this cell on the WH-1000XM2 with ANC and Bluetooth active simultaneously. The BMS accepted the cell without error flags, charge termination triggered correctly at 4.2V, and protection cutoff fired at the expected low-voltage threshold without requiring a manual reset.
• ANC circuit draw management: The WH-1000XM2 runs its noise-cancellation processor continuously when ANC is enabled. Turning ANC off when not needed reduces the combined draw on the cell and slows voltage sag during extended use — this matters most on a freshly replaced cell during its first few charge cycles.

Why the WH-1000XM2 shows full charge but ANC cuts out after light use

A degraded cell loses capacity unevenly — the voltage curve stays flat near the top then drops sharply. The headphone's fuel gauge reads that flat section as "full" and gives no warning before the ANC processor loses its minimum voltage and shuts off. A new 1050mAh cell restores the full voltage curve so the gauge tracks accurately again. After fitting this replacement, run two full charge-discharge cycles with ANC active to let the BMS re-calibrate its state-of-charge model.

Audio distorting on the WH-1000XM2 before the battery indicator reaches empty

The headphone amplifier needs a stable voltage above roughly 3.4V to drive the 40mm drivers cleanly. When the cell sags under combined amp and radio load, the amplifier clips before the battery indicator has reached its low threshold — you hear distortion but the indicator still shows bars remaining. This is a cell impedance problem, not a driver fault. Replacing the cell restores the voltage headroom the amplifier needs; if distortion persists after fitting a new cell, check the solder joints on the battery connector.