The New SAE G-27 Packaging Standard and Beyond

In late 2024, a significant milestone was reached in the world of battery transport safety: the approval of the first SAE G27 packaging standard. While this approval marks a promising step forward, it’s important to understand the nuances of what this standard entails and what challenges still remain for the committee to address.

What Is the SAE G27 Packaging Standard?

The new SAE G27 packaging standard aims to develop packaging solutions capable of containing a thermal runaway event entirely within the box. This means if a lithium battery—or multiple lithium batteries—undergoes thermal runaway during transport, the packaging must prevent any flame or fragments from escaping, minimize external heat generation, and most critically, ensure that any off-gas released does not ignite.

What Makes the New Standard Challenging?

The requirements for the new SAE G27 packaging standard compliance are stringent. For example, it’s not enough for a package to just withstand flames or high temperatures. It must also contain gases that may be flammable or reactive. If these gases ignite within the test chamber, the packaging fails the test. This makes the design of compliant packaging incredibly complex, especially since traditional materials like cardboard or plastic often fall short. 

As the SAE G27 committee worked on developing the new standard, important considerations and insights became apparent as extensive testing and analysis took place, including:

• Matching the Package to the Battery
• The packaging must be tailored to the specific type of batteries or cells being shipped. Some lithium-ion cells may produce only minimal heat and off-gassing when forced into thermal runaway. In such cases, even simple packaging might suffice. Conversely, more volatile batteries can release intense heat, flames, and fragments, making them incompatible with basic materials and necessitating advanced, metal-based packaging with integrated thermal performance features.
• Scaling Up: The Propagation Effect
• Another major consideration is scalability. Testing typically involves initiating thermal runaway in a single battery within a package and evaluating the effects. But what happens when you’re shipping a hundred batteries in the same box? A single failure could cascade into a chain reaction, where one cell’s failure triggers the next, and so on. This propagation effect adds another layer of complexity to the design and testing of compliant packaging.

Current Limitations and Future Prospects

The currently approved G27 standard is narrowly focused, applying only to lithium-ion cylindrical cells. It was approved by the SAE but has not yet been adopted by any government body. As of now, there’s no legal requirement mandating the use of G27-compliant packaging. However, it’s foreseeable that regulatory agencies may eventually adopt such requirements, especially for high-risk shipments.

The road ahead involves expanding the standard’s applicability to other battery formats like pouch and prismatic cells, as well as lithium metal and emerging chemistries such as solid-state and sodium-ion batteries.

Ongoing Efforts and Commitment

The committee behind G27—including long-standing contributors—remains committed to the goal of improving transport safety. While the journey is far from over, and implementation could still be years away, each step forward brings us closer to safer, more reliable battery transport across the globe.

The development of the G27 standard underscores the importance of aligning packaging solutions with the specific behaviors of different battery types, especially under failure conditions. As the market evolves and new battery technologies emerge, so too must the standards that ensure their safe transport.