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Battery standard steps up

The adoption of a new battery product standard is an important step forward for the storage industry.

By Clean Energy Council Executive General Manager, Installation Integrity Sandy Atkins

The battery storage industry has been around for a long time, but it is currently undergoing a major makeover. With new battery products being developed at a rate of knots, the trickiest part of knowing what product standard should apply is understanding what battery product you have.

This may sound simple, but there are a number of ways that battery energy storage systems (BESS) can be manufactured. These systems can be broadly categorised into three groups:

  1. installer-assembled battery systems (DC outputs)
  2. pre-assembled battery systems (DC outputs)
  3. pre-assembled BESS (integrated with inverter — AC output).

Let’s start with the last one first as it is the easiest to explain. These systems generally do not have any DC connections that the installer needs to wire (some may require DC cabling but these are pre-manufactured by the BESS manufacturer). As the output of these systems is AC, they connect to the electrical installation in the same way that a grid-connect inverter does. Examples of these types of systems are Sonnen, Tesla Powerwall 2, Enphase and Redback.

A pre-assembled battery system is made by a company that manufactures the batteries and control systems as one product. The installer is not able to replace individual cells within the battery system. This system may be a complete unit or it may be modular, where battery modules can be added to expand the amount of storage.

The output of these systems is DC, meaning the designer determines which inverter is connected to the battery system. The installer needs to install the DC cables and possibly the over-current protection and switches for the DC connection of these systems to the inverter. Examples of these are LG Chem, BYD and Solarwatt.

The last system is a more traditional off-grid installation. This is where the designer specifies the battery system components, batteries, control systems, over-current protection and inverter. These systems are commonly made up using individual lead acid battery cells. The installer then assembles the battery system on site and quite often builds the battery system enclosure.

The product standard that a battery system should be certified to comes down to which system is being used. Standards Australia recently announced the Australian adoption of international standard IEC 62619. AS IEC 62619:2017 (secondary cells and batteries containing alkaline or other non-acid electrolytes – safety requirements for secondary lithium cells and batteries, for use in industrial applications), which covers safety requirements for secondary lithium cells and batteries for use in stationary and motive applications.

The Australian adoption of this standard is a good step forward for manufacturers of lithium battery systems and BESS. There had been discussions about whether this product standard was applicable to home battery systems due to the wording in the title that references industrial applications. The Australian adoption overcomes this confusion and states in the preface that the standard can be used for residential and commercial application.

In addition to this product standard, the energy storage industry is working with regulators, energy networks, CSIRO and product certifiers to develop and publish an industry-agreed best practice battery equipment guide.

The guide is based on information, risks, safety issues, test/assessment and mitigation processes that are currently applied and meet an acceptable safety outcome. It will outline different pathways that manufacturers of lithium battery systems and BESS can follow to show designers, installers and consumers that they have assessed the risks associated with their products and how they have addressed these. The Australian standard will probably form part of one of the pathways, but there may be other international standards that are appropriate.

The Australian standard and industry-agreed best practice battery equipment guide are invaluable to ensuring that preassembled battery systems and BESS are manufactured to battery product standards that are the best in the world.

This leaves installer-assembled battery systems. As these are constructed on site, it is not possible to have the whole system certified. Therefore, it is important to ensure that the designer selects individual components that meet the requirements for each device. The Clean Energy Council’s Battery Installation Guidelines for Accredited Installers outlines a number of standards that may be applicable.

Therefore, if you are looking at installing pre-assembled battery systems or BESS, ask your manufacturer what product standards it has been tested to. Also keep an eye on our website and installer newsletter as this is a major focus area for the CEC in 2018.

This article was first published in the February 2018 edition of ecogeneration.