Sony MDR-XB950N1 Replacement Battery 3.7V 1000mAh LIS1553

Sony MDR-XB950N1 / WH-CH700N / SRS-WS1 — 3.7V Li-Polymer Replacement Battery (LIS1553)

This is a 3.7V, 1000mAh Li-Polymer replacement cell for the Sony MDR-XB950N1, WH-CH700N, and SRS-WS1. It replaces OEM part LIS1553 (also listed as A-2215-026-A and LIS1553HNPCS). Fit this battery when the original cell no longer holds a charge, cutting out active noise cancellation or dropping wireless audio mid-use.

• MDR-XB950N1, WH-CH700N, and SRS-WS1 compatibility: All three models share the LIS1553 cell format — same 3.7V nominal rail, same connector pinout, and the same BMS handshake protocol used by Sony's onboard charge controller. Swapping the cell does not require firmware changes or pairing resets.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on an MDR-XB950N1 unit. The BMS accepted the new cell without error flags, completed a full charge cycle, and noise cancellation drew correctly without triggering undervoltage cutoff.
• First-cycle charge protocol for the MDR-XB950N1: Place the headset on charge from flat before the first listening session. The onboard controller uses the initial charge cycle to calibrate the fuel gauge — skip this and the battery indicator will misread state-of-charge for the first several uses.

Why the MDR-XB950N1 cuts out when ANC and audio run together

Active noise cancellation and Bluetooth audio draw simultaneously from the same cell. On a degraded battery, the combined current pull drops cell voltage below the BMS cutoff threshold — the headset shuts off even though the indicator showed charge remaining. A fresh LIS1553 cell raises the usable voltage floor, keeping the combined draw above cutoff. If the new cell still cuts out, check that the first full charge cycle was completed — a cell that has never been fully charged will hit its floor earlier than rated.

Talk time shorter than expected on the first few uses

Li-Polymer cells ship at storage voltage — roughly 3.85V — not at full capacity. The onboard fuel gauge on the WH-CH700N and MDR-XB950N1 reads this as a partial charge and estimates talk time accordingly. Real capacity increases over the first three to five full charge-discharge cycles as the cell's electrolyte stabilises. Run three complete cycles — charge to full, use until the headset shuts off — before treating the talk-time indicator as accurate.