I. Pre-export Testing and Documentation Preparation
According to the General Administration of Customs, lithium-ion batteries (UN3480/3481) and lithium-metal batteries (UN3090/3091) are classified as dangerous goods under the UN Recommendations on the Transport of Dangerous Goods – Model Regulations. Three fundamental preparations must be completed prior to export: first, UN38.3 testing—batteries must pass a series of tests (including altitude simulation, thermal cycling, vibration, shock, external short circuit at 55°C, impact, overcharge, and forced discharge) with reports issued by a professional testing agency;
second, the Material Safety Data Sheet (MSDS)—this must be the standard, complete 16-section version and must align with the actual specifications of the goods; and third, transport condition assessment—for air transport, the assessment report must be issued by an agency authorized by the Civil Aviation Administration of China (CAAC). These documents are prerequisites for subsequent packaging assessment and customs declaration.
II.
Two Stages of Dangerous Goods Packaging Inspection
Under the Law on Import and Export Commodity Inspection, lithium battery shipments that have not obtained qualified packaging assessment are prohibited from export.
The first stage is packaging performance inspection: the packaging manufacturer applies to the local customs authority, obtains a manufacturer code for dangerous goods packaging, and submits the packaging for testing; upon passing, a “Certificate of Inspection Results for Packaging Performance of Import/Export Goods” is issued, typically valid for no more than 12 months from the date of manufacture.
The second stage is packaging usage assessment: the lithium battery manufacturer applies for this, and customs conducts an on-site verification of packaging type, securing/protection measures, warning labels, and other factors; upon passing, a “Certificate of Assessment Results for the Use of Packaging for Outbound Dangerous Goods” is issued. This certificate is generally valid for 12 months for sea and land transport, but only for 3 months for air transport.
Lithium batteries complying with Special Provision 188 of the TDG regulations are exempt from formal classification testing but must bear the specific rectangular lithium battery mark on the packaging.
III.
Customs and Maritime Declarations
Export declarations are processed via the International Trade “Single Window” system; the product name, quantity, and specifications must match the actual goods.
For sea transport, additional filings with maritime authorities are required: a “Report on Safe Carriage of Dangerous Goods” (Cargo Declaration) and an “Application for Permit to Carry Dangerous Goods In/Out of Port” (Vessel Declaration). These declarations must be handled by certified dangerous goods declarants and accompanied by documents such as the Declaration of Safe Carriage, Safety Data Sheet (SDS), and Container Packing Certificate. Container packing must comply with the “Technical Requirements for Safe Packing of Dangerous Goods in Containers for Sea Transport.”
For large equipment such as energy storage containers (e.g., UN3536 lithium-ion battery energy storage systems), attention must also be paid to container certification and stowage requirements.
IV.
Packaging, Labeling, and Transport Requirements
Lithium battery packaging must comply with Packing Instruction P903, meeting the Packing Group III performance standard, with adequate internal cushioning, securing, and short-circuit protection; heavy batteries (12 kg or more) require robust outer packaging or pallet support.
Outer packaging must clearly display the UN number, Class 9 dangerous goods label, lithium battery handling label, and watt-hour (Wh) rating; certain categories are restricted to cargo aircraft only and must bear the “Cargo Aircraft Only” label.
For sea-transported energy storage cabinets, attention should also be paid to recommended State of Charge (SOC) levels (e.g., SOC ≤ 50%) and equipment power-off requirements.
V.
Common Risks and Recommendations
Common industry risks center on three areas: first, incomplete or expired documentation (e.g., the model number in the UN38.3 report does not match the shipped batteries); second, the use of packaging documentation intended for one mode of transport (sea vs. air) for the other, leading to inspection failure; and third, discrepancies between declared parameters and the actual goods, triggering customs holds or targeted inspections.
It is recommended that exporting enterprises pre-screen the complete set of documentation, engage professional agents experienced in dangerous goods declarations, and allow sufficient time for inspections and the submission of supplementary information.
Conclusion
The customs declaration process for exporting energy storage components can be summarized by the following principles: prioritize testing, conduct dual inspections of packaging, ensure compliant declarations, and maintain complete labeling.
Standardizing the process and assigning specific personnel responsible for each step can significantly reduce uncertainties in customs clearance and ensure that energy storage products are delivered to overseas projects on schedule.
