BBU · Battery Backup Unit
Rack-level battery that rides through power dips and absorbs sudden GPU load swings before the BESS or genset reacts.
Rack-mounted battery providing short ride-through and load-transient smoothing for AI racks.
Also written as: Battery Backup Unit
Current numbers
<2 ms ramp after ~2 ms qualificationORv3 BBU v1.4 ramp to full power after the low-voltage qualification interval (OCP specification, September 2023); ≥46 V bus requirement
up to 97% VFI vs >99% ECO/VFDLiebert EXL S1 UPS efficiency in double-conversion (VFI) and ECO modes; a central UPS figure, not the ORv3 BBU