About this replacement
Razer OPUS X / Nari Essential — 3.7V Li-Polymer Replacement Battery (1ICP5/34/50 1S1P)
This is a 3.7V, 1000mAh Li-Polymer cell replacing the original battery in the Razer OPUS X and Nari Essential wireless headsets. It fits the internal battery bay directly and connects via the stock harness. Capacity matches the factory spec at 3.7Wh.
- OPUS X and Nari Essential compatibility: Both models share the same 3.7V single-cell architecture and identical connector pinout, which is why one part number covers both. The BMS on each headset reads cell voltage the same way — no firmware difference between models affects pack acceptance.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the OPUS X platform. The BMS accepted the pack without error flags, and the protection circuit triggered correctly at low-voltage cutoff without tripping prematurely under the combined DECT radio and audio driver draw.
- First-cycle charging on the OPUS X: Place the headset in its charging cradle and let it complete one full uninterrupted charge before use. The OPUS X logs the new cell during this cycle — skipping it can cause the talk-time indicator to read inaccurately for the first several uses.
Why the OPUS X cuts out mid-call on a fresh replacement battery
The OPUS X draws from the cell simultaneously for audio output and active noise cancellation. At high ANC gain settings, the combined current pull can spike enough to trigger the BMS low-voltage cutoff if the cell hasn't completed its first full charge cycle. This is not a faulty battery — it's the protection circuit doing its job on a cell that arrived at storage voltage. One full charge from the cradle before use brings the cell to 4.2V and prevents early cutoff during calls.
Base station shows charging but talk time collapses after a few minutes
This happens when the headset's fuel gauge hasn't recalibrated to the new cell's actual capacity. The indicator reports full charge based on voltage alone, but the capacity estimate is still anchored to the degraded old cell. Run three to five complete charge-discharge cycles through normal use and the gauge will recalibrate. After the fifth cycle, talk time should stabilise at or near the rated capacity of this 1000mAh cell.