About this replacement
Microsoft Surface Headphones 2 — 3.7V Li-Polymer Replacement Battery (563439P)
This 3.7V, 450mAh Li-Polymer cell replaces the OEM 563439P battery inside the Microsoft Surface Headphones 2. It powers both the audio playback circuit and the active noise cancellation system simultaneously. Swap it in when the original cell no longer holds a usable charge across a full listening or call session.
- Surface Headphones 2 fit: The 563439P cell runs a single-cell 3.7V rail shared by the Bluetooth radio, ANC processor, and audio amplifier. This replacement matches the original cell's footprint at 36.70 × 21.90 × 5.00mm and uses the same connector orientation, so the BMS handshake with the headset's charge controller completes normally.
- Bench tested on actual hardware: We cycled this cell under combined ANC-plus-audio draw and confirmed the protection circuit holds the low-voltage cutoff without premature shutdown. Charge acceptance from the USB-C port behaved identically to the factory cell across multiple cycles.
- First-cycle charging on Surface Headphones 2: After fitting the new cell, charge via USB-C until the LED indicator shows full before playing audio or enabling ANC. The headset's onboard fuel gauge needs one complete charge cycle to calibrate its capacity reading — skipping this step causes the battery indicator to read inaccurately for several sessions.
Why Surface Headphones 2 cuts out when ANC and audio run together
Active noise cancellation draws continuous current from the same cell that powers the audio amplifier and Bluetooth radio. On a degraded or newly installed cell at storage voltage, the combined load briefly pulls the terminal voltage below the BMS cutoff threshold. The headset interprets this as a depleted cell and shuts down, even if the charge indicator showed capacity remaining. A full charge cycle before first use brings the cell to peak voltage and gives the BMS enough headroom to handle the combined draw without tripping.
Battery indicator stuck at full but headset shuts off after a short session
This happens when the replacement cell arrives at storage voltage — typically around 3.6–3.85V — and the headset's fuel gauge hasn't recalibrated to the new cell's actual capacity. The gauge reports what it expects based on the previous charge state, not what the new cell can deliver. Run the headset down to the auto-shutoff point, then charge it fully via USB-C without interruption. After one complete discharge-and-charge cycle, the capacity reading aligns with actual cell state.