Ocean freight is the workhorse for lithium battery logistics — power tools, e-mobility products, energy storage systems, and replacement packs for the Caribbean and Latin American markets all flow through South Florida’s ports. But lithium batteries are fully regulated Class 9 dangerous goods under the IMDG Code, and carriers have tightened acceptance sharply after a series of high-profile vessel fires. Getting a booking accepted, and keeping it accepted at the gate, takes preparation.
Here is what shippers and forwarders moving batteries through PortMiami and Port Everglades need to know.
Know your UN number first
Everything downstream depends on classification:
- UN3480 — Lithium ion batteries shipped on their own (standalone cells or packs, including power banks)
- UN3481 — Lithium ion batteries packed with equipment or contained in equipment (a drill shipped with its battery, a laptop with the battery installed)
- UN3090 / UN3091 — the lithium metal equivalents (non-rechargeable chemistry)
- UN3171 — Battery-powered vehicle or battery-powered equipment, used for certain vehicles and equipment powered by wet batteries; note that lithium-battery-powered vehicles have their own entries under recent editions of the regulations, so classify vehicles carefully against the current IMDG amendment
Watt-hour rating, cell versus battery, and quantity per package determine which packing provisions apply, including the smaller-battery provisions of Special Provision 188 that allow simplified requirements for low watt-hour cells and batteries.
Core IMDG requirements
Packaging
Except where the small-battery provisions apply, lithium batteries require UN specification packaging meeting the applicable packing instruction (P903 and related instructions for batteries; separate instructions cover damaged and waste batteries). In all cases, batteries must be protected against short circuit, secured against movement, and packed to prevent contact between terminals and conductive materials. Loose batteries tossed in a gaylord will fail inspection — and have started fires.
State of charge
By air, IATA limits standalone UN3480 lithium-ion batteries to 30% state of charge. For ocean, state-of-charge expectations have been tightening: recent IMDG amendments and, just as importantly, individual carrier policies increasingly require a reduced state of charge (commonly 30% or less) for standalone lithium-ion shipments. Verify the current amendment in force and your specific carrier’s DG policy before production units ship — some lines demand SoC certification at booking.
Marks and labels
Depending on size and configuration, packages need the Class 9 lithium battery label (Class 9A), the UN number and proper shipping name, and for shipments under the small-battery provisions, the lithium battery mark with the UN number and a telephone number for additional information. Overpacks must be marked accordingly. Container-level placarding applies once packages go into a box.
Documentation
Fully regulated shipments require a dangerous goods declaration under the IMDG Code, and when you load the container yourself, a container packing certificate confirming proper stowage, securing, and segregation. Errors here are the number one cause of booking rejections. Go Hazmat’s mobile hazmat documentation service prepares compliant DG declarations on-site at shipper facilities across South Florida, which is often faster than bouncing drafts back and forth with an overseas documentation desk.
Booking DG cargo out of PortMiami and Port Everglades
Ocean carriers treat lithium batteries as restricted commodities, which means the booking process has extra steps:
- DG approval before booking confirmation. Submit the DG request with UN number, packing group data (Class 9 has none, but watt-hour and net quantity details matter), packaging type, and SDS or test summary references. Carriers’ DG desks can take several days — build that into vessel schedules.
- UN 38.3 test summary availability. Manufacturers and distributors must make the lithium battery test summary available; carriers and forwarders increasingly ask for it at booking.
- Terminal cutoffs are earlier for DG. Both PortMiami and Port Everglades terminals enforce earlier in-gate cutoffs for hazardous cargo, and some accept DG only on specific days. A missed DG cutoff means rolling to the next vessel.
- Drayage needs a hazmat-qualified driver. The trucking leg to the terminal is regulated by DOT rules, including placarding and shipping papers. Go Hazmat runs drayage near both ports with vetted hazmat drivers, and our Miami warehouse handles staging, labeling checks, and repacking when cargo arrives in non-compliant condition.
Why lithium battery bookings get rejected
From what we see at the ports, the most common rejection reasons are:
- DG declaration errors: wrong UN number, missing watt-hour data, mismatch between declaration and physical cargo
- Missing or incorrect lithium battery marks and Class 9A labels
- No UN 38.3 test summary when the carrier requests one
- Damaged cartons or evidence of crushed packaging at the terminal gate
- Undeclared batteries discovered in “general cargo” — which can lead to fines and blacklisting with that carrier, not just a rolled booking
- Attempting to ship damaged or recalled batteries under standard provisions
Damaged, defective, and recalled batteries
This category deserves its own warning. Batteries that are damaged or defective — including units recalled for safety reasons — may not be shipped under the normal provisions. The IMDG Code requires special packaging provisions for damaged/defective batteries, and cells liable to rapidly disassemble or produce a dangerous heat effect require competent authority approval before transport. They are forbidden for air transport entirely. If you are handling a recall or a fire-damaged inventory lot in Florida, talk to a specialist before anything moves; our hazmat consultation team scopes these projects regularly, and improper movement of recalled batteries is an enforcement priority.
The Miami advantage — if you prepare
South Florida is one of the best gateways in the country for battery exports to Latin America and the Caribbean: frequent sailings, short drayage, and a deep bench of DG-experienced providers. The shippers who move batteries smoothly through PortMiami are the ones who classify early, lock the DG approval before promising delivery dates, and stage cargo at a compliant facility near the port so a labeling problem is fixed in hours, not sailings.
Frequently asked questions
Can I ship lithium-ion batteries at full charge by ocean?
For standalone lithium-ion batteries (UN3480), you should plan for a reduced state of charge. Air transport caps UN3480 at 30% state of charge, and ocean carriers — along with recent IMDG amendments — increasingly require reduced charge levels for standalone lithium-ion shipments as well. Check the current IMDG amendment and your carrier’s dangerous goods policy before shipping, as requirements are tightening.
What documents do I need to ship UN3480 by sea from Miami?
Fully regulated shipments need a dangerous goods declaration under the IMDG Code, a container packing certificate if you load the container, and the UN 38.3 lithium battery test summary available on request. The carrier will also require DG approval at booking, with details including the UN number, watt-hour ratings, packaging type, and net quantities. Marks, labels, and placards must match the paperwork exactly.
Can I ship recalled or damaged lithium batteries by ocean?
Not under standard provisions. Damaged and defective lithium batteries, including recalled units, must be shipped under special IMDG packaging provisions, and batteries liable to rapidly disassemble or produce dangerous heat require competent authority approval before transport. They are forbidden by air. Engage a dangerous goods specialist before moving any damaged or recalled battery inventory.