I. Determine Classification: Categorization by UN Number
Under the UN Recommendations on the Transport of Dangerous Goods, energy storage batteries are classified as Class 9 dangerous goods. The correct UN number must be determined prior to transport: UN3480 for standalone lithium-ion batteries; UN3481 for those packed with or contained in equipment; UN3090/UN3091 for lithium-metal batteries; UN3536 for containerized lithium-ion battery energy storage systems; and UN3556 for lithium-ion battery-powered vehicles. As of March 31, 2025, lithium battery-powered vehicles are no longer classified under UN3171 and must be declared using the new UN numbers. Incorrect classification will directly result in shipment refusal by the carrier or even administrative penalties.
II.
Prerequisites for Transport: UN38.3 Testing and Packaging Inspection
Lithium batteries must first pass the UN38.3 series of tests (comprising eight tests: altitude simulation, thermal cycling, vibration, shock, external short circuit at 55°C, impact, overcharge, and forced discharge) and obtain the corresponding test report and test summary;
these are mandatory prerequisites for transport. For maritime exports, two additional packaging inspections are required: the packaging manufacturer must apply to Customs for a packaging performance inspection to obtain the “Inspection Result Sheet for Performance of Packaging for Import/Export Goods,” and the battery manufacturer must apply for a packaging usage assessment to obtain the “Assessment Result Sheet for Use of Packaging for Export Dangerous Goods.”
The validity period for these documents is generally 12 months for maritime and land transport, but only 3 months for air transport.
III. Strict Limits on State of Charge (SoC)
Restrictions on the State of Charge (SoC) have been a key focus of tightened regulations in recent years.
Regarding air transport, in accordance with IATA’s *Dangerous Goods Regulations* (DGR), lithium-ion batteries shipped in isolation must not exceed a state of charge (SoC) of 30% of their rated capacity. Effective January 1, 2026, this 30% limit will also apply to lithium-ion batteries with a rated energy exceeding 2.7 Wh when shipped “packed with equipment”; exceeding this limit requires written approval from the competent authorities of both the state of origin and the state of the operator, and transport is restricted to cargo aircraft only. For battery-powered vehicles, the battery SoC must not exceed 30%, or the indicated capacity must not exceed 25%.
Regarding maritime transport, industry best practice recommends that energy storage cabinets and battery packs be delivered for shipment at a low SoC (e.g., around 30%) to mitigate the risk of thermal runaway and comply with the requirements of certain shipping lines.
Lowering the SoC has been proven to significantly reduce the probability of thermal runaway.
IV.
Packaging, Labeling, and Marking Requirements
In accordance with Packing Instruction P903, lithium-ion battery packaging must meet Packing Group II performance standards, featuring internal protection against short circuits and movement, and must pass a 1.2-meter drop test in any orientation; packages exceeding 400 kg may utilize Large Packaging Instruction LP903.
Packages must be marked with the Proper Shipping Name and UN number (minimum height of 12 mm) and, where applicable, display the Class 9 dangerous goods label, the lithium battery handling mark, and the “Cargo Aircraft Only” label; battery casings must be marked with the rated energy (Wh) in accordance with Special Provision SP348.
For container transport, Class 9 placards (minimum 250 mm x 250 mm) and UN numbers (digit height minimum 65 mm) must be affixed to all four sides of the container; for containerized energy storage systems (UN3536), placards must be affixed to opposite sides.
Starting in 2025, the “Lithium Battery Label” will be renamed the “Battery Label” and its scope will be expanded to include sodium-ion batteries.
V. Declaration Documents and Stowage/Segregation
For maritime exports, a qualified dangerous goods declarer must submit a “Dangerous Goods Safety and Suitability Report” (Cargo Declaration) and an “Application for Vessel Port Entry/Exit” (Vessel Declaration) to the maritime authorities. Required accompanying documents include the Safety Data Sheet (SDS), transport condition assessment materials, and packaging inspection certificates;
the carrying vessel must hold a valid Certificate of Fitness for the Carriage of Dangerous Goods. Container loading must comply with GB 40163 standards: packages must be securely lashed, the center of gravity kept low and near the container’s center, and the goods must not be packed with flammable/explosive materials or sharp metal objects.
For deck stowage, it must be ensured that the fixed water-based fire-extinguishing system provides effective coverage.
For air transport, the Shipper’s Declaration for Dangerous Goods, the Acceptance Checklist, and the Notification to Captain (NOTOC) must be completed and submitted.
VI. Notice on 2026 New Regulations
The 67th edition of the IATA DGR came into effect on January 1, 2026. Requirements such as mandatory State of Charge (SoC) limits, new UN numbers for sodium-ion batteries (UN3551/3552) and corresponding packing instructions, a new 3-meter stacking test requirement, and updates to Cargo IMP codes for vehicles must be implemented in advance.
For the EU market, attention must also be paid to the associated requirements regarding transport packaging, recycling labeling, and carbon footprint as stipulated in the 2023 Battery Regulation (Regulation (EU) 2023/1542).
Conclusion
The requirements for the export and transport of energy storage batteries can be summarized in six key actions: assigning UN numbers, passing tests, controlling charge levels, managing packaging, preparing documentation, and ensuring proper segregation.
Integrating the latest IMDG and IATA DGR rules into Standard Operating Procedures (SOPs)—and updating them in line with annual regulatory changes—is essential to ensuring the safe and smooth export of energy storage products.
