The growing use of rechargeable battery-powered products is changing the way warehouses are designed, operated, and protected. Portable power stations, rechargeable tools, household appliances, mobility products, and consumer electronics now rely heavily on lithium-ion and other rechargeable battery chemistries.
What was once a limited storage concern has become a broader fire protection challenge for manufacturers, distributors, recyclers, and authorities having jurisdiction (AHJs).
Battery use today
The trend is clear. Products that once used single-use batteries are increasingly being replaced by rechargeable, multi-use alternatives.
Battery collection and recycling data also show the scale of this shift. In Europe, sales of portable batteries and accumulators increased from about 160,000 tons in 2009 to 231,000 tons in 2023, while waste battery collection increased from about 50,000 tons to 117,000 tons. In the United States, Call2Recycle reported collecting 9.7 million pounds of batteries in 2024, including about 6.6 million pounds of rechargeable batteries and 3.3 million pounds of single-use batteries. Out of which more than 4 million pounds were lithium-ion batteries.
Battery storage hazards
Before these products reach the end user, they are often stored in warehouses like other commodities. However, large quantities of batteries can pose hazards beyond ordinary combustible storage, including thermal runaway, fire spread, flammable gas generation, deflagration potential, and emergency response challenges. Where an individual battery-powered product/battery presents a limited hazard, bulk storage can raise significant concerns for local fire marshals and the surrounding community.
Code and standard requirements
Historically, model fire codes focused more heavily on battery systems than on battery storage as a warehouse commodity. The International Fire Code (IFC) introduced a dedicated chapter, Chapter 12, Energy Systems, in the 2018 edition. National Fire Protection Association (NFPA) 1, Fire Code, previously contained Chapter 52 for stationary lead-acid battery systems, which later evolved toward broader energy storage system provisions. NFPA 855, Standard for the Installation of Stationary Energy Storage Systems, was first introduced in 2018. These requirements mainly addressed energy storage hazards, but they did not fully address how batteries should be protected when stored in warehouses.
Code updates. The 2024 IFC update added Section 320, Lithium-Ion and Lithium Metal Battery Storage, under Chapter 3 for general storage, or as renumbered by local amendment. NFPA 855 also includes requirements for lithium-metal and lithium-ion battery storage in Chapter 14.
Together, these provisions reflect a move away from a broad commodity approach and toward a hazard-specific approach based on battery chemistry, state of charge, quantity, and storage arrangement.
Applicability of the requirements. Both the IFC and NFPA 855 include important exceptions, including the following:
· Batteries installed in the equipment, devices, or vehicles they are intended to power are generally exempt.
· Batteries packed with such equipment may also be exempt.
· Small consumer batteries in original retail packaging may fall outside the more restrictive requirements for lithium-ion batteries rated at not more than 300 watt-hours or lithium-metal batteries containing not more than 25 grams of lithium metal.
These exceptions help separate ordinary retail or packaged product storage in smaller retail facilities from larger warehouse storage conditions that require more detailed review.
State of charge (SoC) is another key factor. Transportation and shipping regulations often limit lithium-ion batteries to a maximum SoC of 30%. Where batteries are documented and maintained at 30% SoC or less, certain requirements may be reduced.
However, this does not mean the storage is always free of battery storage-specific code requirements. In jurisdictions that have adopted an IFC-based model fire code, storage exceeding 15 cubic feet, approximately the volume of two 55-gallon drums, can still trigger an operational permit (when adopted by the AHJ), fire safety plan, automatic sprinkler protection, and an automatic detection for the indoor battery storage areas.
Damaged, defective or recalled (DDR) battery requirements. Additional requirements may apply to damaged, defective, or recalled batteries, commonly referred to as DDR batteries. These batteries may not qualify for the same exceptions as new batteries or batteries in original packaging. Their SoC may also be unknown or difficult to control.
As a result, fire-resistance-rated separation or dedicated cutoff rooms, dedicated outdoor storage, explosion control, or specialized storage arrangements may be needed. Recycling, refurbishment, and collection operations should evaluate these issues early, as DDR battery storage can pose a different hazard than new-product storage.
Outdoor lithium-ion battery storage
Outdoor storage provisions address the hazard through separation distance, pile size, pile height, and detection. The IFC generally requires outdoor lithium-ion and lithium-metal battery storage to be at least 20 feet from buildings, lot lines, public ways, and means of egress, unless additional protection features allow a reduction.
Outdoor piles are generally limited to 900 square feet, 10 feet in height, and at least 10 feet of open space between piles. Radiant energy-sensing or thermal imaging detection may also be required because the storage is outdoors.
High-piled storage
Based on the storage arrangement, high-piled combustible storage requirements can also apply. In jurisdictions that follow the IFC model codes, Chapter 32 may become applicable when battery storage exceeds 6 feet in height, unless modified by the AHJ. Lithium-ion batteries and certain dry cell vehicle batteries are classified as high-hazard commodities in Chapter 32, Table 3206. This classification may trigger requirements such as
· Smoke and heat vents
· Fire department access doors
· Pile-size limitations
· Automatic sprinkler protection
Fire sprinkler system requirements
Sprinkler protection remains one of the most difficult issues for a design aspect. NFPA 13 provides sprinkler criteria for many storage arrangements, but it does not provide a complete prescriptive protection scheme for lithium-ion batteries or other battery chemistries containing combustible electrolytes. As a result, current practice often relies on insurer guidance, particularly FM Data Sheet 7-112, Lithium-Ion Battery Manufacturing and Storage.
The FM Data Sheet provides protection schemes based on the storage conditions, including state of charge, packaging, storage height, ceiling height, aisle width, and rack arrangement. In general, lithium-ion batteries stored at less than 60 percent SoC may be protected without in-rack sprinklers, where the storage arrangement and building limitations are met. Where those limits are exceeded, or where SoC is above 60%, rack storage may require in-rack sprinklers and horizontal barriers. DDR batteries generally require a more conservative approach, such as a cutoff room, outdoor storage, or enhanced rack protection.
European guidance takes a similar hazard-based approach but classifies the hazard differently. VdS Schadenverhütung GmbH, commonly referred to as VdS, uses stored battery energy in VdS 3856, with categories such as less than 1 kilowatt-hour, 1 to 50 kilowatt-hours, and more than 50 kilowatt-hours per storage unit. VdS CEA 4001, developed with reference to the Comité Européen des Assurances (CEA) sprinkler rules, and Technical Bulletin 003 provides additional sprinkler guidance for lithium-ion battery storage.
In simple terms, FM guidance places more emphasis on SoC, while VdS guidance places more emphasis on stored energy per storage unit and storage configuration.
Early involvement of a fire protection engineer
Because the hazard depends on chemistry, SoC, packaging, storage arrangement, and battery condition, the codes rely heavily on technical evaluation from qualified fire protection engineers.
Under the IFC, a technical opinion report may be required to evaluate protection requirements, sprinkler design, explosion control, and thermal runaway hazards. NFPA 855 contains a similar requirement in Section 14.5.2, which requires a written hazard analysis prepared by a registered design professional with fire protection engineering expertise to be submitted to the AHJ for review and approval.
Conclusion
The practical message is clear: battery storage in warehouses can no longer be treated as routine commodity storage. Occupancy classification, code exceptions, permit thresholds, high-piled storage requirements, outdoor separation, hazard analysis, sprinkler design, and emergency response planning should be addressed early.
The proposed NFPA 800, Battery Safety Code, is also expected to continue this shift toward hazard-based assessment and lifecycle battery safety requirements. Early involvement of a qualified professional, such as an experienced and licensed fire protection engineer, is essential to evaluate applicable AHJ requirements and develop practical, approvable protection strategies that help make the facility and surrounding community safer and more sustainable.
