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
3–5% vs >99%central UPS: double-conversion loss vs eco-mode / advanced-standby efficiency (Vertiv Liebert EXL S1 datasheet) — a UPS figure, not the ORv3 BBU
~50% / 2–3%battery-capacity cut and double-conversion-loss cut from distributed BBU + supercaps vs central 2N
<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