If you import electronics, cordless tools, scooters or anything rechargeable, you are importing lithium batteries. And with them, the category of dangerous goods that stops more shipments than any other in the world.
The good news is that they move every day. What you need to understand is how they are declared, what documentation they require, and why aircraft are far stricter than ships.
In this guide
Why lithium is regulated
A lithium battery stores a lot of energy in a small space. If it suffers a short circuit, an impact or a manufacturing defect, it can go into thermal runaway: a process where it heats itself up at an accelerating rate until it catches fire.
The problem in transport is that this fire feeds itself. It does not need external oxygen the way an ordinary fire does, which makes it very hard to extinguish inside a closed hold with nobody able to intervene for hours or days.
That is why they are classified as class 9 — miscellaneous dangerous goods, and why the rules are stricter by air than by sea: on a vessel there are systems and reaction time that simply do not exist mid-flight.
UN numbers: how your battery travels
The first thing that determines the treatment is how the battery travels, not what the product is. There are four cases:
| UN number | Situation | Typical example |
|---|---|---|
| UN3480 | Lithium-ion batteries shipped alone | A batch of spare batteries |
| UN3481 | Lithium-ion contained in or packed with equipment | Laptops, phones, drills |
| UN3090 | Lithium metal batteries shipped alone | Non-rechargeable lithium cells |
| UN3091 | Lithium metal in or with equipment | Devices with a backup cell |
Which one applies to your product is stated in the safety data sheet and the manufacturer's technical documentation.
The documents you will need
- UN38.3 test summary. The document certifying the battery passed the eight United Nations safety tests. It is mandatory and issued by the manufacturer. What it is and how to request it is covered in this guide.
- Safety data sheet (SDS/MSDS) for the product or the battery.
- Shipper's declaration, prepared by the freight forwarder.
- Approved packaging and packages carrying the corresponding labels.
Without the UN38.3 there is no shipment: it is the first document a carrier looks for when it sees the word lithium.
Air or ocean
This is the decision with the greatest impact on a shipment involving batteries.
| Ocean (IMDG) | Air (IATA DGR) | |
|---|---|---|
| Restrictions | More flexible | Considerably stricter |
| Volumes | Handles large quantities | Limited |
| State of charge | No general requirement | Batteries shipped alone travel partially charged |
| Cost | Lower | Higher, plus DG surcharges |
| Best for | Commercial volume | Urgent needs and small quantities |
On state of charge: for air transport of lithium-ion batteries shipped on their own, the regulations require them to travel partially charged rather than full. It is a measure to reduce the energy available in the event of an incident. The exact percentage and the conditions that apply are confirmed by the carrier for each shipment.
In practice: if you are bringing commercial volume, ocean freight is almost always the way. Air freight is for urgent cases, and you should expect more restrictions and higher cost.
What to ask your supplier for
Since most of this electronics comes from Asia, this fits into the normal flow of importing from China. Ask while quoting, not while paying:
- The UN38.3 Test Summary for the cell or battery
- The safety data sheet for the product
- The UN number that applies given how it will be shipped
- Whether the battery ships alone, inside the equipment or packed with it
- Watt-hours (Wh) per battery and number of batteries per package
Mistakes that stop these shipments
- Assuming "it is just a device". If it has a rechargeable battery, there are dangerous goods involved. More examples in products that are dangerous goods without looking like it.
- Asking for the UN38.3 last. If the manufacturer does not have it, there is no shipment — and that is far better known before paying.
- Accepting a UN38.3 for a different model. The report corresponds to a specific cell or battery, not to the brand in general.
- Declaring the wrong UN number. Confusing 3480 with 3481 changes the entire treatment of the shipment.
- Mixing loose batteries with equipment in the same package without declaring it correctly.
- Choosing air out of habit. With batteries, air can complicate a shipment that would be straightforward by sea.
Frequently asked questions
Can lithium batteries be imported into Costa Rica?
Yes. They are transported regularly, both on their own and inside equipment. What they require is specific documentation — chiefly the UN38.3 test summary and the safety data sheet — and prior approval from the carrier, because they are class 9 dangerous goods.
What is the difference between UN3480 and UN3481?
UN3480 covers lithium-ion batteries shipped on their own, such as a batch of spares. UN3481 covers those inside equipment or packed alongside it, such as laptops or cordless tools. The treatment of the shipment changes depending on which applies, so it is worth confirming with the supplier before shipping.
Do I need the UN38.3 if the battery comes inside the product?
Yes. The battery being installed does not remove it from the regulations: the UN number changes, but the UN38.3 test summary is still required. It is one of the misunderstandings that stops the most shipments.
Is it better to ship them by air or by sea?
For commercial volume, almost always by sea: ocean freight is considerably more flexible with lithium batteries. Air has considerably stricter restrictions, quantity limits and higher costs, so it is best reserved for urgent needs or small quantities.
What if my supplier does not have the UN38.3?
That is a serious warning sign. Every cell or battery manufacturer has been required to make that report available since 1 January 2020. If they do not have it, those goods will struggle to ship through formal channels — and it is worth reconsidering whether that is the right supplier before transferring money.
Written by the VS Logistics team.
Bringing in products with batteries?
Send us the UN38.3 and the safety data sheet from your supplier — or tell us what you want to import — and we will confirm how it is declared and which route makes sense.