About this replacement
SteelSeries Arctis 9X / PDP LVL50 — 3.7V Li-Polymer Replacement Battery (FT603048P)
This is a 3.7V, 850mAh Li-Polymer cell (FT603048P) for the SteelSeries Arctis PDP LVL50 and Arctis 9X wireless headsets. It replaces the original pack when the headset no longer holds a charge or cuts out during use. Dimensions are 50.80 × 30.00 × 6.00mm — the same footprint as the factory cell.
- Arctis 9X and PDP LVL50 compatibility: Both models run the same 3.7V single-cell architecture with an identical connector and BMS handshake profile. One cell covers both headsets without any modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Arctis platform. The BMS accepted the pack cleanly — no protection trip, no charge refusal, and the base station reported charging state correctly after the first full cycle.
- First charge on a new cell: Seat the headset in the base station and let it complete a full, uninterrupted charge cycle before using it. The base station logs the new cell during this cycle — skipping it causes the talk-time estimate to read inaccurately for several sessions.
Voltage sag under combined audio and wireless radio draw
The Arctis 9X and LVL50 run audio processing and the wireless radio simultaneously from a single 3.7V cell. Under that combined load, a weakened or deeply discharged cell can sag below the BMS cutoff threshold even when the indicator still shows charge remaining. A fresh cell at full charge holds voltage more steadily under this dual draw. If cutouts happen early in a session, check that the first full charge cycle completed before the headset was used.
Base station shows full but headset cuts off after a short time
This happens when a new cell arrives at storage voltage — typically around 3.6V — and the base station misreads it as already charged. The headset then runs off a cell that was never fully topped up. The fix is straightforward: place the headset on the base and leave it until the charge indicator completes a full cycle from flat. After one full charge from a low state, the base station recalibrates and the behaviour stops.