NB-BESS OPEN STANDARD
Industrial energy category

NB-BESS: No-Break Battery Energy Storage System

The category of industrial energy storage that never lets the grid touch your load. Zero-millisecond continuity of a double-conversion UPS, at the scale and economics of a plant-level BESS.

Read the Standard v1.1 What is an NB-BESS?

An open category standard · Founded by PulseVolt, creator of the NB-BESS™ technology · Open to all manufacturers

Definition

The canonical definition maintained by the NB-BESS Open Standard initiative.

An NB-BESS (No-Break Battery Energy Storage System) is an industrial energy storage system that powers a facility continuously through a double-conversion path, so that grid disturbances — voltage sags, transients, micro-interruptions, and outages — never reach the load. Unlike a UPS, it scales to full-plant loads. Unlike a conventional BESS, it has no transfer time. Unlike a generator, it responds in zero milliseconds.

NB-BESS Open Standard · Definition 1.0 · 2026
01 / CONTINUITY

Zero-millisecond transfer

The load is served through the inverter at all times. There is no switch, no synchronization gap, no transfer event — the disturbance simply never arrives.

02 / SCALE

Plant-scale power

Sized for complete production lines or entire facilities — a floor of 500 kW continuous, scalable to MW-class — not for a single server rack or machine.

03 / ECONOMICS

Working storage

The same battery that protects production performs peak shaving and tariff optimization, so the asset pays for itself instead of sitting idle.

Why a new category exists

A production line rarely stops because energy is missing. It stops because of the quality of the energy.

The failure mode nobody's spec covered

Voltage sags and micro-interruptions of a few milliseconds trip robots, servo drives, SMT lines, and validated processes — followed by hours of restart, scrap, and re-validation. Backup generators start in seconds. Conventional BESS transfers in milliseconds. Both are too slow for the event that actually causes the loss.

The gap between UPS and BESS

Double-conversion UPS technology solves continuity but was never engineered for full-plant loads and does nothing for the energy bill. Grid-scale BESS solves economics but tolerates transfer time. The NB-BESS category exists because industry needs both properties in one system — and until now there was no name, and no rules, for it.

NB-BESS vs UPS vs BESS vs generator

Where the category sits — and why the distinction is a specification, not marketing.

PropertyUPSConventional BESSGeneratorNB-BESS
Transfer time0 ms (device scale)ms–secondsSeconds–minutes0 ms at plant scale
ScaleDevices / IT roomsPlant / gridPlantLine to full plant (MW-class)
Power quality conditioning 24/7Yes, at its scaleNo — grid-coupledNoYes — continuous double conversion
Rides through micro-interruptionsYes, at its scalePartiallyNoYes, by architecture
Backup durationMinutesMinutes–hoursDays (with fuel)Minutes–hours, generator-extensible
Energy cost optimizationNoYes — core functionNoYes — peak shaving on the same asset
Asset utilizationIdle until an eventWorking dailyIdle until an eventWorking daily + protecting always

Reference architecture

The defining trait: the plant is always served from the inverter. The grid charges the system; it never powers the load directly.

Grid disturbances Rectifier AC → DC DC bus energy buffer always energized Battery storage MW-class · peak shaving Inverter serves load 24/7 Plant load maintenance bypass — outside the critical path transfer time: 0 ms (there is nothing to transfer)
NB-BESS reference architecture — double conversion with plant-scale storage on the DC bus. The load never sees the grid.

The Standard, in brief v1.1 · 2026

A system may be designated an NB-BESS only if it meets all ten normative criteria — each anchored, where one exists, to an established UL, IEC or IEEE standard. Full text, verification methods and conformance process: NB-BESS Open Standard v1.1.

N-1

Zero-transfer continuity

Load served through the conversion stage at all times; output classified VFI-SS-111 per IEC 62040-3; 0 ms transfer by architecture.

N-2

Continuous power conditioning

Load bus held inside the ITIC envelope 24/7, SEMI F47 where applicable, ≤5% output THD at rated load.

N-3

Industrial scale

Continuous rated output not less than 500 kW, with an architecture scalable to MW-class loads.

N-4

Bridging and backup

Zero-interruption ride-through plus declared rated autonomy of at least 5 minutes at full load, generator-extensible without a transfer event.

N-5

Enforced protection reserve

Peak shaving and tariff optimization permitted — but no command, schedule or operator action may discharge below the reserve. Not covered by any existing standard.

N-6

Measurable availability

Power quality measured and logged to IEC 61000-4-30 Class A, events classified per IEEE 1159, records retained 12 months and exportable.

N-7

Storage safety certification

UL 9540 listing with UL 9540A data and UL 1973 components; installation to NFPA 855 and local code.

N-8

Conversion safety certification

Conversion stage certified to UL 1778 and/or IEC 62040-1, carrying the declared IEC 62040-3 classification.

N-9

Multi-source DC coupling

Two or more independent sources — utility, generation, PV — with no load-bus disturbance on any source transition. Not covered by any existing standard.

N-10

Supervision and integration

Classified alarms with remote notification, and monitoring data exposed over an open protocol without a proprietary gateway.

Read the full Standard v1.1 → Annex A — Test Methods (PDF) ↓

NB-BESS Open Standard seal

Origin of the category

The term NB-BESS™ and its underlying architecture were created by PulseVolt, an industrial resilience infrastructure company. PulseVolt filed patent applications with the USPTO for the technology, and operates MW-class NB-BESS systems in continuous service at high-precision manufacturing plants — automotive, aerospace, electronics, medical devices, and food & beverage.

In 2026, PulseVolt founded the NB-BESS Open Standard initiative and published the category criteria openly, becoming its first conformant manufacturer. The initiative welcomes any manufacturer whose systems meet the standard — a category is only real when it is bigger than one company.

Visit PulseVolt →
NB-BESS™ is a trademark of PulseVolt. The standard text is published under an open license; the trademark identifies conformance with the standard.

Frequently asked questions

The questions engineers and plant managers ask first.

What is an NB-BESS?
An NB-BESS (No-Break Battery Energy Storage System) is an industrial energy storage system that powers a facility continuously through a double-conversion path, so grid disturbances — voltage sags, transients, micro-interruptions, and outages — never reach the load. It combines the zero-millisecond continuity of a double-conversion UPS with the plant-scale capacity and energy economics of a BESS.
How is an NB-BESS different from a UPS?
A UPS typically protects individual devices or IT loads at limited power levels, and its batteries sit idle except during events. An NB-BESS applies the same no-break principle at industrial scale — full production lines or entire plants, up to MW-class — and its storage also works daily on energy optimization such as peak shaving.
How is an NB-BESS different from a conventional BESS?
A conventional BESS is optimized for energy economics and backup, but it is coupled to the load through a transfer or synchronization step — milliseconds to seconds of exposure during grid events. An NB-BESS serves the load through its inverter at all times, so there is no transfer time at all: zero milliseconds.
Does an NB-BESS replace a backup generator?
For short and medium events, yes — it rides through sags, micro-interruptions, and outages of seconds to hours with zero interruption. For multi-day outages, an NB-BESS combines with a generator: the NB-BESS provides instant continuity while the generator provides long-duration energy.
Why do plants need zero-millisecond transfer?
High-precision manufacturing — automotive robotics, SMT lines, aerospace machining, validated pharma and medical processes — can scrap product or halt for hours after a disturbance of a few milliseconds. A line rarely stops because energy is missing; it stops because of the quality of the energy. Zero transfer time is the only specification that eliminates that exposure entirely.
Who created the NB-BESS category?
The term NB-BESS™ was coined by PulseVolt, which filed USPTO patent applications for the technology and operates MW-class systems in continuous industrial service. PulseVolt founded this open standard initiative in 2026 and is its first conformant manufacturer.
Can other manufacturers build NB-BESS systems?
Yes. The standard is published openly so any manufacturer can design against its criteria and declare conformance — see the conformance process. The goal is a recognized category, not a single-vendor label.