Power banks, e-bikes and lithium batteries by sea: what to have ready before booking

Quick answer: Yes — power banks, e-bikes and lithium-ion batteries ship by sea as Class 9 dangerous goods. Standalone batteries are UN 3480, batteries packed with or contained in equipment are UN 3481, complete vehicles are UN 3171. You need a UN 38.3 test report and Test Summary from an accredited lab, IMDG packing (the P903 family), Class 9 marks and a dangerous goods declaration. Sea sets no state-of-charge limit — the 30% rule is air-only.

Why sea is the default for lithium cargo

Air and sea regulate the same batteries differently, and the gap is wide enough to route whole industries. In the air, UN 3480 is forbidden on passenger aircraft, capped on cargo aircraft, and each battery must be at or below 30% state of charge when it flies — IATA's Dangerous Goods Regulations, implementing the ICAO Technical Instructions. At sea, the IMDG Code classifies the same batteries as Class 9 miscellaneous dangerous goods, requires the documents and packing described below, and sets no state-of-charge limit at all.

Air rules summarized from the IATA Dangerous Goods Regulations; sea rules from the IMDG Code. Individual carriers apply their own variations on top — confirm at booking.

The practical consequence: production volumes of batteries, power banks and battery-powered vehicles move by sea, and air remains the exception for urgent UN 3481 cargo or small, compliant UN 3480 quantities. If your supplier quotes you a "sea only" policy on batteries, that is regulation doing its job, not the supplier being difficult.

Which UN number applies to your cargo

Everything downstream — packing, marks, carrier acceptance — follows from the UN number, so get it right first:

The distinction between "with the vehicle" and "on its own" is where shippers get caught. An e-bike rolling into a container with its battery installed is a vehicle; the same battery in a separate carton is a standalone battery with the full UN 3480 treatment. Confirm which one your packing list actually describes before anything is booked.

The document set

Four documents come with a compliant sea shipment of lithium batteries:

• UN 38.3 test report. The battery must have passed the UN 38.3 test series — altitude, thermal, vibration, shock, external short circuit, impact, overcharge, forced discharge — at an accredited laboratory, for the exact model you are shipping. A model change means a new report.
• Test Summary. The standardized summary required by section 38.3.5 of the UN Manual of Tests and Criteria; the battery producer issues it and the shipper forwards it with the booking.
• Safety data sheet (SDS). The carrier's DG desk reviews it against the UN number and proper shipping name.
• Dangerous goods declaration. States the UN number, proper shipping name, hazard class and packaging; signed by the shipper. This is the document the terminal and the vessel act on.

Two failure modes we see repeatedly: self-made test reports, which carriers reject on sight, and certificates that do not match the battery model in the box — the certificate is per model, not per company. Check both before the factory books the truck to the CY.

Packing, marks and labels

Packing follows the IMDG packing instruction family: P903 for UN 3480, and P903, P967 or P970 for UN 3481 depending on the configuration. The physics the instructions protect against is the same in every case — terminals short-circuiting and cells moving in transit — so batteries are individually protected, cushioned against movement, and boxed in strong outer packaging. Each package then carries the Class 9 lithium battery label and the lithium battery mark with the UN number.

Wooden crates count as wood packaging: if heavy packs are crated, the crates must be ISPM 15 heat treated and stamped. And the line that has no workaround — damaged, defective or recalled batteries are not shippable as ordinary dangerous goods; they move only through specialized disposal and recovery channels.

The DG booking sequence

Dangerous goods bookings follow the same five steps on every lane:

Steps 1 and 2 are where the calendar is won or lost. Documents take as long as the laboratory and the producer take — start them when the production order starts, not when the container is on the yard. How containers are loaded and braced once accepted is on the container loading guide; the FCL-versus-LCL trade-off for restricted cargo is on the FCL vs LCL page.

Boundary conditions

• LCL acceptance is the exception, not the rule. Consolidators pack other people's cargo beside yours; many decline standalone UN 3480 entirely, and those that accept it restrict quantity and position. Confirm in writing at quotation.
• Carrier limits on UN 3480. Some services cap the quantity per box or per vessel, or take UN 3480 only on direct rotations. The booking answer comes from the carrier's DG desk, not from the rate sheet.
• State of charge at sea. No rule sets it, and 30% or below remains the cheapest fire-risk reduction available — some carriers ask for it as a condition of acceptance anyway.
• Customs treatment differs by destination. Duty on batteries, power banks and vehicles depends on the HS code in the destination tariff — confirm per product. The transport rules above are mode rules, not tax rules.
• Suppliers without documents. A factory that cannot produce a UN 38.3 report for the model you are buying is telling you something. Walk away or change the model.