UL 9540

Energy Storage Systems and Equipment

Also written as ANSI/CAN/UL 9540

Current edition
3rd edition
Published
2023-06-28
Last verified
2026-08-22

Base edition confirmed and re-verified 2026-08-22. The third edition is being revised in place (residential installation annex, March 2027 compliance date); no fourth edition is established.

What it covers

The system-level listing standard for energy storage in North America. Where the component standards address cells and batteries, this one addresses the assembled product — the battery, conversion equipment, controls and enclosure evaluated together as a complete system. A UL 9540 listing is the certification most often named in permitting and procurement documents.

Editions

  1. 3rd edition In force 2023-06-28

    The third edition remains the base document but is under active revision. A revision approved in March 2025 added a new annex covering residential energy storage installation instructions, carrying a compliance date of March 2027.

  2. 2nd edition Superseded

Next edition & pipeline

Targeted2027

No fourth edition. The third edition is being revised in place — the March 2025 revision (residential installation annex) carries a March 2027 compliance date.

Official source

learnBESS doesn't host or reproduce standards. Read or purchase the document from the issuing body.

View UL 9540 at UL Standards & Engagement ↗

Standards change quietly. Get told when they move.

A low-volume email for people who write specs: when a BESS standard changes edition or enters revision, you hear about it.

No spam. Unsubscribe anytime.