Fire Protection Engineering For Lithium Ion Battery Storage

After many years of development, the codes and standards related to storage of lithium ion battery cells still offer more questions than answers. There are many different use cases for lithium ion batteries, each with different levels of risk, and the currently adopted codes only address a small subset of these cases. In this blog post I will provide some references that Fire Protection Engineers can use when researching solutions for Lithium Ion Battery-related hazards.

We must start by acknowledging what we all know, that the code provides very little guidance when it comes to this topic. Many of us are familiar with the requirements of NFPA 855 for fire protection of Energy Storage Systems. NFPA 855, however, is not adopted into the North Carolina Fire Code. It is also only applicable to Battery Energy Storage Systems with capacities over 20 kWh. Where do we find guidance for Battery Energy Storage Systems under 20 kWh, or lithium ion batteries that are not being used in Energy Storage Systems? I expect NFPA 800 to address these situations, but no drafts have been released yet.

The 2018 North Carolina Fire Code and 2018 North Carolina Building Code specifically exclude lithium ion batteries from the hazardous commodity protection criteria. We can look at the 2024 International Fire Code Section 320 which provides guidance for some storage scenarios, but excludes lithium ion batteries in original retail packaging rated less than 300 Watt hours and lithium ion batteries installed in the devices they are meant to power, among other things.

For the storage of lithium ion batteries excluded from the 2024 IFC, such as storage of lithium ion battery powered power tools, we have guidance from Datasheets and Technical Reports published by FM (formerly known as FM Global). The first document you should read is “Development of Protection Recommendations for Li-ion Battery Bulk Storage: Sprinklered Fire Test” published in 2016 by FM. This report provides guidance for warehouse storage of 20Ah “large format” pouch cells in ceilings heights up to 40 ft and storage heights up to 15ft. FM also published Datasheet 7-112 “Lithium Ion Battery Manufacturing and Storage.” This Datasheet provides specific protection criteria for rack storage of Li-Ion cells.

Another publication worth reading is the Fire Protection Research Foundation’s “Lithium Ion Batteries Hazard and Use Assessment.” This report provides an assessment of the potential fire risks associated with transport and storage of lithium ion batteries.

As you read through the literature on this topic, you will notice that there are two cell criteria that are often mentioned when assessing the associated fire risks: State of Charge and Cell Capacity. Any conversation about how to protect lithium ion battery cells must include these characteristics of the cells involved. Your protection criteria must include them as well.