About this replacement
Razer Barracuda X — 3.7V Li-Polymer Replacement Battery (ACE503450)
This 3.7V, 1200mAh Li-Polymer cell replaces the internal battery in the Razer Barracuda X wireless gaming headset. It fits the Barracuda X directly, matching the original ACE503450 specification at 4.44Wh. Swap it when the original cell no longer holds charge through a full gaming or listening session.
- Barracuda X battery fit: The Barracuda X uses a single 3.7V Li-Polymer cell to power both the audio driver and the 2.4GHz wireless radio simultaneously. The ACE503450 footprint — 52.30 × 33.70 × 6.00mm — matches the original cell housing with no modification needed.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Barracuda X unit, confirming the BMS accepted the new pack without a charging error and balanced current draw across the combined audio and wireless radio load.
- First-charge protocol for Barracuda X: Seat the headset in the USB-C charging position and run a complete charge before first use. The headset's internal fuel gauge needs one full cycle to calibrate the new cell — skipping this causes the charge indicator to read inaccurately for the first several uses.
Voltage sag under combined audio and 2.4GHz radio draw
The Barracuda X pulls current from a single small cell for two simultaneous loads — the audio amplifier and the wireless radio. When the cell ages and internal resistance rises, voltage sags briefly during radio transmission bursts. The BMS reads this as a low-cell condition and triggers a cutoff to protect the pack. A fresh ACE503450 cell has lower internal resistance, so the voltage rail stays stable under the same combined load.
Charge indicator shows full but headset cuts off after short use
This happens when a new cell ships at storage voltage — typically around 3.6–3.7V — and the headset's fuel gauge hasn't yet mapped the cell's actual capacity. The indicator reads "full" based on voltage alone, but the usable capacity estimate is wrong. Run one complete charge cycle from flat to full via USB-C and the gauge will recalibrate. After that cycle, the charge readout tracks correctly against the rated 1200mAh capacity.