When you specify a kWh-scale lithium battery energy storage system (ESS) for a project in another country, the product's datasheet is only half the story. The battery also has to physically travel to the site — and lithium batteries are regulated as dangerous goods in transport under a global framework that applies whether you ship by sea, air, or road. For importers, distributors, EPC contractors, and C&I project buyers, the real question is whether the battery can be lawfully and safely moved, and what your supplier and forwarder must have in place before you book freight. This guide explains the rules and gives you a pre-booking checklist.
Direct answer To ship lithium battery energy storage systems internationally, confirm that the exact battery type has passed the applicable UN38.3 tests and that its test summary is available. The shipper must then determine the correct UN number, packing instruction, marks, labels, state-of-charge controls and documents for the specific configuration and transport mode. These requirements differ by shipment, mode, route and carrier, so obtain written acceptance from a dangerous-goods-qualified forwarder and the carrier before booking.
1. Why lithium battery storage is regulated in transport
Under the UN Model Regulations on the Transport of Dangerous Goods, lithium cells and batteries are classified as Class 9 — Miscellaneous dangerous goods because, if damaged, short-circuited, or exposed to the stresses of transport, they can overheat, enter thermal runaway, and cause a fire (UNECE, UN Model Regulations). This classification is global: it flows into the modal rules used for each transport mode.
This applies to lithium iron phosphate (LiFePO4) systems too. LiFePO4 is a lithium-ion chemistry, so it is subject to the same lithium-battery transport rules as other lithium-ion batteries — the generally lower energy density and thermal stability of LiFePO4 are material to product safety, but they do not change its dangerous-goods classification in transit.
The hierarchy of rules is:
- UN Model Regulations set the global classification, UN numbers, and test basis.
- IMDG Code (International Maritime Dangerous Goods Code, published by the International Maritime Organization) governs sea transport.
- ICAO Technical Instructions, implemented operationally by the IATA Dangerous Goods Regulations (DGR), govern air transport.
- ADR (the UNECE European Agreement concerning the International Carriage of Dangerous Goods by Road) and RID (rail) govern overland movement in many regions.
For a buyer, the important control is not to assume that appointing a forwarder transfers every duty. Obtain exact-model test and classification evidence, identify the legal shipper or consignor and packer for the transaction, and confirm acceptance with a qualified forwarder and carrier before booking. Duties vary by contract, mode and jurisdiction.
2. UN38.3 — the pre-shipment test every battery must pass
UN38.3 is not a marketing certificate and it is not a quality grade. It is a defined set of transport safety tests described in Section 38.3 of Part III of the UN Manual of Tests and Criteria (UNECE, UN Manual of Tests and Criteria). Lithium cells and batteries must pass these tests before they can be offered for transport.
The T.1–T.8 sequence covers altitude simulation, thermal cycling, vibration, shock, external short circuit, impact or crush, overcharge and forced discharge. The exact applicability depends on whether the tested article is a cell or battery and on its design.
Crucially, UN38.3 is a test and a test summary, not a certificate with an open-ended validity period. Since the 2020 edition of the UN Model Regulations, a UN38.3 Test Summary must be made available through the supply chain so that downstream parties (forwarders, carriers, and buyers) can verify it on demand. As a buyer, your concrete action is to request the UN38.3 Test Summary for the exact battery model you are purchasing — not a generic brand statement — and keep it with your shipping documents.
3. Class 9, UN numbers, and how an ESS is classified
Lithium batteries are assigned specific UN numbers that tell carriers exactly what they are handling:
| UN number | Covers |
|---|---|
| UN 3090 | Lithium-metal cells/batteries, shipped alone |
| UN 3091 | Lithium-metal cells/batteries, in or with equipment |
| UN 3480 | Lithium-ion cells/batteries, shipped alone |
| UN 3481 | Lithium-ion cells/batteries, in or with equipment |
4. Sea, air and road — what changes by mode
The dangerous-goods framework is shared, but the operational rules diverge by mode. Always confirm the specifics with your forwarder, because carriers and national authorities add variations.
Sea (IMDG Code, IMO). Lithium-ion batteries move under the applicable IMDG entry and packing instruction, commonly using UN 3480 or UN 3481 depending on whether they are shipped alone, packed with equipment or contained in equipment. Packaging must protect against short circuits and damage, but the exact instruction and UN performance-packaging requirement depend on battery mass and configuration. The IMDG Code 2024 Edition incorporating Amendment 42-24 is mandatory from 1 January 2026 (IMO, IMDG Code). Confirm stowage, segregation and carrier requirements before booking.
Air (ICAO Technical Instructions, implemented by IATA DGR). Standalone lithium-ion (UN 3480) and lithium-metal (UN 3090) batteries are forbidden on passenger aircraft and may only travel on cargo aircraft (CAO). A key control is state of charge (SoC): standalone lithium-ion batteries (UN 3480) generally must not exceed 30% of rated capacity when offered for air transport, per the ICAO Technical Instructions and IATA DGR; shipments above that limit require approvals from the States of origin and the operator (CAAS Singapore, Advisory Circular AC 92-2-1, implementing ICAO TI). From the IATA DGR 67th Edition (effective 1 January 2026), the ≤30% SoC requirement also became mandatory for lithium-ion batteries packed with equipment (PI 966) above small energy thresholds (IATA, Lithium Batteries). Note that SoC rules for air and sea are not identical — confirm the mode-specific limit with your carrier. Damaged or defective batteries are forbidden by air.
Road and rail (ADR / RID, UNECE). Overland movement in many regions follows the same Class 9 / UN-number logic with SP188 thresholds and possible national variations (UNECE, ADR).
The single most common cause of rejected or delayed battery shipments is assuming one mode's rule applies to another. Confirm the mode-specific packing, marking, labelling, SoC, and documentation requirements before you book.
5. Buyer's checklist — what to request and confirm before booking
Treat transport compliance as a precondition, not an afterthought. Before you commit to a shipment of lithium battery ESS:
- Request the UN38.3 Test Summary for the exact battery model from your supplier, and confirm it is available through the supply chain.
- Confirm the correct UN number (typically UN 3480 or UN 3481 for LiFePO4/lithium-ion) and that the shipment will be declared as Class 9 dangerous goods.
- Confirm the applicable packing instruction and packaging standard for the exact battery mass, configuration and transport mode.
- Confirm the required marks and labels for the applicable UN number, packing instruction, section and mode; do not assume every package uses the same combination.
- Confirm state-of-charge handling for the mode — air typically ≤30% SoC for UN 3480; sea per IMDG/SP188 — and obtain the SoC declaration from your supplier.
- Engage a dangerous-goods-qualified freight forwarder and confirm carrier acceptance, including any State or country variations that may apply on the route.
- Confirm import-side requirements with your local competent authority (customs / dangerous-goods authority), as some markets add documentation or approvals at destination.
A compliant shipment avoids the delays, rework, and potential rejection of a consignment that cannot clear dangerous-goods checks — compared with one documented correctly from the start.
Frequently asked questions
Do lithium battery energy storage systems require UN38.3 testing? Yes. Under the UN Model Regulations, lithium cells and batteries — including LiFePO4 ESS — must pass the UN38.3 tests (Section 38.3 of Part III of the UN Manual of Tests and Criteria) before transport. A UN38.3 Test Summary must be available through the supply chain; request the one for your exact battery model from your supplier.
Are lithium battery storage systems Class 9 dangerous goods? Yes. Lithium batteries are classified as Class 9 (Miscellaneous dangerous goods) under the UN Model Regulations because of thermal-runaway and fire risk in transport. A kWh-scale ESS sits far above the SP188 small-battery relief thresholds, so it is fully regulated as Class 9, not exempt.
What UN number applies to a LiFePO4 battery storage system? LiFePO4 is a lithium-ion chemistry, so it is normally declared as UN 3480 (lithium-ion batteries shipped alone) or UN 3481 (packed with or contained in equipment), both as Class 9. The exact UN assignment depends on how the system is packed and should be confirmed with your supplier and a dangerous-goods specialist.
Can lithium battery storage be shipped by air? It can, but with restrictions. Standalone lithium-ion batteries (UN 3480) are forbidden on passenger aircraft and may move only on cargo aircraft, and are generally limited to ≤30% state of charge for air transport; damaged or defective batteries are forbidden by air. Sea and road rules differ — confirm mode-specific requirements with your carrier.
What documents should I request from my supplier before booking battery freight? At minimum, request the UN38.3 Test Summary for the exact model, the proposed UN number and transport description, the applicable packing instruction, the marks and labels required for that shipment, and any state-of-charge evidence required for the mode. Engage a dangerous-goods-qualified freight forwarder to confirm carrier acceptance.
SH Energy is a Global Energy Storage Solutions Provider for commercial, industrial and residential projects. Availability of a UN38.3 Test Summary and transport documents is confirmed for the exact selected model before quotation or shipment. Send the model, quantity, destination and intended transport mode to jimmy@sunhongenergy.com for a document-availability check.
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