Lithium-ion batteries are fantastic — until they are treated like ordinary cargo. Because they are classified as dangerous goods, a shipment missing the right test reports, packaging or labeling can be refused by airlines, seized by customs, or fined heavily. Importing batteries (or products containing them) from China requires getting compliance right before the goods leave the factory.
This guide covers the test that matters most (UN38.3), the 100 Wh and 160 Wh air thresholds, the packaging and documentation rules, and what to demand from your supplier.
UN38.3: the test your supplier must already have
UN38.3 is the UN Manual of Tests and Criteria subsection that every lithium cell and battery must pass before transport. It is a sequence of eight tests covering altitude simulation, thermal extremes, vibration, shock, external short circuit, impact/crush, overcharge, and forced discharge.
You must ask the supplier for the UN38.3 test summary from a recognized lab, tied to the exact cell/battery model you are buying. A generic “we have UN38.3” without a model-matched report is not enough — if the model changes, testing must be repeated. Without it, carriers will not accept the cargo.
The 100 Wh and 160 Wh thresholds
Air transport rules hinge on watt-hours (Wh), which must be marked on the battery itself:
- Up to 100 Wh — batteries and battery packs are accepted under the standard lithium battery rules with approved packing, generally without case-by-case airline approval.
- Over 100 Wh up to 160 Wh — requires the airline operator’s approval, and strict limits on how many can be shipped; this is the ceiling for spare batteries carried on passenger aircraft.
- Over 160 Wh — cannot be shipped as ordinary cargo or passenger baggage; they move only as fully regulated dangerous-goods cargo under a shipper’s declaration.
Wh is calculated as voltage (V) × capacity (Ah). Confirm the marking on the physical cell matches the specification sheet — mismarked or unmarked batteries are a common rejection reason.
Air, sea and packaging rules
- Air freight follows the IATA Dangerous Goods Regulations (DGR). Lithium-ion batteries shipped alone are UN3480; batteries packed with, or contained in, equipment are UN3481. (Lithium metal cells are UN3090/UN3091.)
- Sea freight follows the IMDG Code, with its own packing and segregation requirements.
- Packaging must be UN specification (UN-marked) strong outer packaging, with each cell protected against short circuit — often in individual pouches or separated trays, inside a UN-approved fiberboard box bearing the UN packaging mark and the lithium battery handling label.
The documents you need before shipping
Insist your supplier hands over the complete compliance packet — the forwarder cannot book the cargo without it:
- UN38.3 test summary, model-matched, from an accredited lab.
- SDS / MSDS (Safety Data Sheet) for the battery chemistry.
- Manufacturer business and export qualifications, and the battery specification sheet stating Wh, voltage and capacity.
- The UN packaging certificate for the outer box, plus the correct lithium battery handling labels and marks applied.
If the goods are built into a device (power banks, wireless earbuds, appliances), confirm whether they ship as UN3481 “packaged with equipment” or “contained in equipment” — the packaging and approval level differ.
Cells vs packs, and standalone vs built-in
Compliance is model-specific, so clarify exactly what you are shipping. Bare cells, finished battery packs, and the same battery built into a device each require their own UN38.3 test summary and their own shipping classification. A pack that combines cells from one maker with a BMS and enclosure from another must be tested as the completed pack — the cell maker’s test does not automatically cover it. If you are importing a finished device with a battery inside (earbuds, power banks, vacuum cleaners), the forwarder still needs the battery’s UN38.3 and SDS on file, even though the device itself is not dangerous goods.
Why shipments get refused — and how to avoid it
The most common rejections are entirely avoidable: a battery with no watt-hour marking on it, a UN38.3 report for the wrong model, ordinary cardboard instead of a UN-marked box, missing labels, or a supplier quietly declaring the cargo as “accessories” to dodge dangerous-goods fees. That last one — misdeclaration — is the worst mistake, because it voids insurance and can trigger carrier fines and customs penalties. Book the cargo honestly as lithium dangerous goods, budget the correct (higher) DG handling fees, and choose a forwarder experienced with battery lanes rather than the cheapest quote.
The bottom line
Treat lithium batteries as dangerous goods from day one, not as a paperwork surprise at the airline. Require a model-matched UN38.3 report, verify the watt-hour marking against the 100/160 Wh thresholds, use UN-approved packaging, and collect the SDS and shipping documents before the container is booked. Done right, battery shipping from China is routine; done wrong, it is a shipment that never moves.