About this replacement
American DJ ULTRA GO PAR7X — 22.2V Li-ion Replacement Battery (Z-ULB249)
This is a 22.2V, 5200mAh Li-ion battery for the American DJ ULTRA GO PAR7X portable LED par fixture. It slots directly into the light's battery bay and powers the LED driver board at the same voltage rail as the original cell. Capacity is rated at 115.44Wh.
- ULTRA GO PAR7X compatibility: The PAR7X runs a constant-current LED driver that requires the full 22.2V nominal rail to hold output steady across all seven LEDs. A lower-voltage pack causes the driver to step down brightness before the battery is depleted, which is why voltage match on this platform matters more than raw capacity.
- Bench tested on actual hardware: We cycled this pack through the PAR7X's LED driver under full RGBWA output. The BMS held the discharge curve flat through mid-cycle and cut off cleanly at the low-voltage threshold without triggering a driver fault.
- Storage charge for the PAR7X between gigs: Store this battery at roughly 50% charge if the fixture will sit unused for more than two weeks. The high-capacity cells in this pack shed capacity faster when stored fully charged at room temperature or above — a common issue for batteries left in flight cases between events.
Why the PAR7X dims before the low-battery indicator triggers
The ULTRA GO PAR7X's LED driver operates in constant-current mode, pulling a fixed current from the battery at all times. As the cell voltage sags under sustained load, the driver can no longer maintain that current without dropping output, so brightness steps down first. The battery indicator reads state of charge, not load-adjusted voltage, so it can still show two or three bars while the light has already dimmed. If you see this early dimming, the pack's internal resistance has likely risen — a new cell at the same nominal voltage restores flat output through the full discharge cycle.
PAR7X won't power on after the battery sat in storage
Li-ion cells self-discharge during storage. If this pack sat unused for several months, individual cells may have dropped below the BMS acceptance threshold — typically around 2.5V per cell — and the BMS will block current flow to protect the cells from an uncontrolled charge. Connect the battery to its charger and leave it for at least 30 minutes before attempting to power the fixture; some chargers apply a low-rate recovery current to bring cells back above the threshold. If the charger shows no activity after 30 minutes, check that cell voltage across the pack reads above 15V before concluding the pack is unrecoverable.