What is the AS 5139 Standard?

AS NZS 5139:2019 (Safety for Battery Energy Storage Systems) is the primary Australian and New Zealand standard governing the safe installation of battery energy storage systems (BESS) connected to power conversion equipment (PCE).

The standard establishes the safety, performance and compliance requirements that are essential for residential and commercial energy storage installations. AS 5139 remains the industry benchmark for safe, reliable and compliant BESS deployment and is a must-have for installers and system designers.

In this article, we explain why the AS NZS 5139:2019 standard is so important, its five-section scope, how to apply or get the standard and how organisations can implement it in the workplace.

AS/NZS 5139:2019 is critical for solar installers, system designers and electrical contractors who deal with battery and energy systems. These professionals should have a sound understanding of the standard due to three key reasons:

• Safety & Performance: Ensures the safe and efficient operation of battery energy storage systems and BESS installations. It reduces the risk of common fire, electric shock, chemical and mechanical hazards.

The risk of a poorly installed battery energy storage system is real, with 4 residential battery energy storage system (R-BESS) fires in New South Wales, with over 456 lithium-ion battery incidents. This shows the importance of properly installed systems that follow the AS/NZS 5139:2019 in reducing common risks.

• Supports Compliance: Required for compliance with state and territory electrical safety regulations to meet the Electrical Regulatory Authorities Council  (ERAC) guidance that was set out in 2021. Failing to do so could create legal and compliance issues for the worker and organisation.

• Increased Control & Efficiency: Provides robust design and installation controls that help professionals demonstrate due diligence and meet regulatory expectations. By implementing AS 5139, it also allows organisations to create a more efficient workflow that reduces claims or incidents that have flow-on effects for productivity.

• New technology and demand: Keeping up with the latest edition ensures organisations are up to date with the latest technology best practices. For example, according to the Australian government Clean Energy Regulator, over 43,517 residential battery systems were installed in just two months from July to August 2025. Given the massive movement towards battery installations and new energy storage systems, the standard is essential for all installers and system designers.
  
  

For anyone installing or designing energy or BESS systems, AS NZS 5139:2019 is essential not only for project approval or compliance, but for the long-term safety of installers and system reliability

The AS NZS 5139 standard applies to battery systems with a nominal voltage between 12 V DC and 1500 V DC and up to 200 kWh per system.

The standard specifies safety requirements for integrated and non-integrated systems and on-site energy storage. This makes it critical for installers and system designers when installing energy systems.

Although there are a total of 7 sections, there are 5 main sections in AS/NZS 5139:2019 to pay closer attention to, these include:

• Section 1—Scope and Referenced Documents: Defines the installation types covered, capacity ranges and technical references used throughout the standard. 

• Section 2—Definitions and System Categories: Provides terminology for battery chemistry types, system components and BESS designs. Specifically, it provides classifications of BESS categories, such as indoor/outdoor or integrated vs non-integrated. 

• Section 3:—Safety Requirements: Covers important hazard identification and mitigation common in energy installation. It explores common potential hazards such as fire protection, chemical safety and electrical shock prevention.

• Section 4—Installation Requirements: Sets out important installation requirements such as clearances, zones and safe installation environments. The section also defines where BESS units can and cannot be installed.

• Section 5—Commissioning and Documentation: Outlines critical post-work or ongoing testing, system commissioning, document creation and other requirements for BESS installations.

• Appendices—Risk Assessment, Signage & Fire-protection Considerations: Includes extensive guidance on other important factors from risk assessments, signage, ventilation and fire protection considerations.

The standard’s wide scope ensures installers or system designers using AS NSZS 5139:2019 can design, implement and document sound practices that meet regulatory, compliance and manufacturer requirements.  

AS NZS 5139:2019 was published on 11 October 2019, and represents the first joint  Australian and New Zealand standard for the safe installation of battery storage systems. 

Before AS 5139, installers relied on older standards such as AS 4086.2 1997 (Secondary batteries for use with stand-alone systems). This standard was less comprehensive and technologically outdated, providing limited guidance on newer high-capacity energy systems. The standard was formally superseded in May 2024.

AS/NZS 5139 consolidates new technology developments with safety principles, fire or risk mitigation and specific controls for a more well-rounded, comprehensive framework. 

Since its publication in 2019, there have been no reviews or amendments, and it remains the current gold standard for energy system installations. Although a technical draft titled ‘AS/NZS 5139:2019’ closed to public comment on 15 August 2025, meaning there could be revisions in the coming years.

Having the AS NZS 5139:2019 standard is just the start, with employers and workers required to implement it on the job. There are a few practical ways installers, system designers and organisations can practically apply the AS 5139 standard:

• Classify the Installation: Determine whether the project is residential or commercial, as different sections of the standard apply differently depending on the installation environment. 

• Identify Correct Battery Zone & Spacing Requirements: Inspect the specific zones and restricted areas for BESS placement based on practical pointers outlined in the standard. These include variables such as wall construction type, exposure to heat or separation distances.

• Apply Risk Mitigation Practices: Workers or organisations can apply practical risk mitigation practices such as better ventilation, correct clearances and internal temperature management to spot potential risks in their workplace or on the job.

• Prepare Consistent Documentation: Providing sound documentation (such as test results, product manuals, maintenance guides, etc) is a practical step for meeting compliance audits. Resources such as the Solar Victoria Checklist or the GSES Overview offer practical tools for implementation.

Not yet compliant? The latest edition is available for purchase at Intertek Inform.

The latest official edition of AS/NZS 5139:2019 is available directly from Intertek Inform. Intertek Inform is a trusted source for official standards and technical publications across many industries. 

Pricing for AS NZS 5139:2019 starts at $321 for a single-user PDF, with a hard copy starting at $357. Prices change depending on the number of users, with higher savings for multi-user PDFs.

When you purchase AS/NZS 5139:2019 through Intertek Inform, users will benefit from:

• Genuine Standards: A trusted and authentic copy direct from Standards Australia
• Immediate Access: Instant PDF downloads with verified licensing
• Multiple Formats: Choose from PDFs, hard copies, or discounted bundles.
• Expert Support: Access to Intertek’s global network of quality and compliance specialists who help you stay compliant

Intertek Inform provides reliable, genuine and updated access to the important standards to get you and your employees safe and compliant.

Shop the AS 5139 Collection now at Intertek Inform.