UN38.3 for Lithium Batteries: Shipping and Compliance

UN38.3 is the test program deciding whether a lithium battery may legally travel by air, sea, road, or rail. Defined in Section 38.3 of the UN Manual of Tests and Criteria, it covers virtually every lithium cell and battery shipped internationally — lithium-ion, lithium-polymer, LiFePO4, and lithium-metal alike. Without a passing UN38.3 test report, batteries should not be on a plane, a ship, or a truck.

For importers buying from China, this is a paperwork problem before it is an engineering one. Testing happens once per battery design, but every shipment depends on the result: the UN number on your cartons, your supplier's packaging, your forwarder's declaration. A sourcing partner that checks test reports upfront catches issues before they become rejected or seized shipments. Below: the eight tests, retesting triggers, shipping classifications, packaging and labeling, mode-by-mode rules, and verifying a factory's report.

What is UN38.3, and which batteries does it cover?

UN38.3 testing for lithium batteries is a set of mechanical, electrical, and environmental stress tests simulating the abuse batteries face in transport. Its official scope is the UN Manual of Tests and Criteria, Section 38.3 — the same reference every transport-mode regulator points back to: IATA for air, the IMDG Code for sea, ADR for European road transport, and the US DOT's 49 CFR. One passing result supports shipping by all four modes.

It covers all lithium chemistries, rechargeable and non-rechargeable: lithium-ion, lithium-polymer, LiFePO4, lithium-metal coin cells, and finished packs assembled from those cells. Size grants no exemption — coin cells and energy-storage packs both need testing.

Two clarifications prevent common confusion. First, there is no "UN38.3 certificate." Labs issue a test report plus a standardized test summary; the summary is the document carriers ask for. Second, UN38.3 covers transport safety only, not whether a battery is safe to use in a product — that belongs to standards like IEC 62133, which many markets require separately for market entry.

Narrow exceptions exist: prototype and low-production runs (usually up to 100 units) sent for testing can move under special provisions such as SP 310 with approved packaging, and damaged or defective batteries face separate, stricter rules. For normal commercial shipments, assume the full requirements apply.

What are the eight UN38.3 tests (T1–T8)?

Every battery must pass each test that applies to it. Not all eight apply to every product: some target cells only, others rechargeable batteries only. Test details below follow published laboratory guidance, including TÜV SÜD's UN 38.3 testing documentation.

Test · What it simulates · Applies to

• T1 — Altitude simulation: Low pressure of an unpressurized aircraft cargo hold (11.6 kPa for 6+ hours) · Cells and batteries, primary and rechargeable
• T2 — Thermal test: Extreme temperature cycling, +72°C down to −40°C, over 10 cycles · Cells and batteries, primary and rechargeable
• T3 — Vibration: Transit vibration (sine sweep 7 Hz–200 Hz–7 Hz, 12 sweeps across three axes) · Cells and batteries, primary and rechargeable
• T4 — Shock: Rough handling and impacts (half-sine pulses, e.g. 150G/6ms for small units) · Cells and batteries, primary and rechargeable
• T5 — External short circuit: A short across terminals at +55°C; case must stay below +170°C with no fire, rupture, or disassembly · Cells and batteries, primary and rechargeable
• T6 — Impact / crush: Mechanical abuse that could cause an internal short (impact test for cylindrical cells over 20 mm diameter) · Cells only
• T7 — Overcharge: Sustained overcharging of a rechargeable unit · Rechargeable batteries and single-cell batteries
• T8 — Forced discharge: Abnormal discharge conditions forced on a cell · Primary and rechargeable cells

The first five tests run in sequence on the same samples, so weaknesses compound: a seal that survives altitude alone can fail after thermal cycling and vibration have worked on it. That is deliberate — transport stresses arrive in combination.

Pass criteria are physical and strict: no mass loss, leakage, venting, disassembly, rupture, or fire, with open-circuit voltage staying within roughly 10% of the pre-test value. Activation of a fuse, current limiter, or venting mechanism is allowed — the protection devices doing their job. If you source packs rather than cells, the test summary lists each test separately, which is how you verify that both the cells and the finished pack were covered.

When is UN38.3 testing required — and when must it be repeated?

Testing must be complete before a battery design is offered for transport — before your first shipment, not after you place an order. If you switch factories or the design changes, confirm the testing covers the exact battery you are buying; a report for a similar-looking model is not automatically valid.

Retesting is triggered by any design change that could cause a test failure. Regulators treat this as a "new type" of battery: different cells, changed protection circuitry or BMS, an altered pack structure or sealing. Cosmetic changes with an identical internal design do not qualify. When uncertain, assume fresh testing is needed — a retest costs far less than a rejected shipment or a thermal incident in transit.

One timing note: testing commonly takes a few weeks, depending on lab queues and complexity, and the thermal test alone runs ten temperature cycles. A factory claiming same-week UN38.3 testing for a brand-new design deserves a hard question — either the tests are already done (fine, ask for the report) or they are not really done.

Which shipping classification applies: UN3480, UN3481, UN3090, or UN3091?

The UN number drives nearly everything downstream: packing instructions, labeling, state-of-charge limits, quantity limits, and whether the goods can fly on passenger aircraft. The logic is simple — battery chemistry plus the battery's relationship to equipment — as Hazmat School's breakdown explains.

UN number · Battery type · How it travels

• UN3480: Lithium-ion (rechargeable) · Cells or batteries shipped alone, not with equipment
• UN3481: Lithium-ion (rechargeable) · Packed with equipment, or contained in equipment
• UN3090: Lithium-metal (primary) · Cells or batteries shipped alone, not with equipment
• UN3091: Lithium-metal (primary) · Packed with equipment, or contained in equipment

A carton of loose lithium-ion power banks is UN3480. The same power banks shrink-wrapped alongside the device they charge are UN3481 "packed with equipment"; installed inside the device, UN3481 "contained in equipment." Lithium-metal coin cells in bulk are UN3090; the same cells inside watches are UN3091. Misclassification between 3480 and 3481 is one of the most common and costly errors in battery freight.

The Watt-hour rating matters for lithium-ion (Wh = nominal voltage × ampere-hours); lithium content in grams is the equivalent measure for lithium-metal. Higher ratings push shipments into stricter packing-instruction sections with smaller package quantities and, by air, cargo-aircraft-only requirements.

What DG packaging and labeling rules apply?

Lithium batteries are Class 9 dangerous goods, and the packaging rules serve one goal: prevent short circuits and contain any failure. These apply whether the shipment is fully regulated or travels under a small-battery exception.

Cells and batteries must be protected against short circuits — terminals insulated or separated so they cannot touch each other or conductive surfaces. Inner packagings must fully enclose each cell or battery, inside a strong rigid outer packaging such as a fiberboard box. Each package must survive a 1.2-meter drop test in any orientation without damage to the cells, without contents shifting enough to allow cell-to-cell contact, and without releasing contents. A supplier cutting corners on cartons is creating a compliance failure, not just a quality complaint — the sort of thing a pre-shipment quality inspection can catch at the factory. The labeling elements to expect:

• The lithium battery mark: a rectangle with red hatched edging showing a group of batteries (one damaged, emitting flame) above the UN number. Minimum 120 × 110 mm, reducible to 105 × 74 mm on small packages.
• The Class 9 hazard label for fully regulated shipments, plus the UN number marking.
• Cargo Aircraft Only labels where required — standalone lithium-ion batteries (UN3480) are forbidden on passenger aircraft.
• Weight limits: under small-battery exceptions such as IMDG/ADR Special Provision 188, packages are typically capped at 30 kg gross.

The Watt-hour rating must be marked on the outside of the battery case for units manufactured after the relevant cutoff dates, and packages need handling information identifying the contents as lithium batteries.

How do air, sea, and ground rules differ?

The UN38.3 result is mode-agnostic; the rules built on top of it are not. Air is the strictest, sea is the workhorse for bulk battery shipments from China, and ground rules vary by jurisdiction.

Air (IATA DGR) · Sea (IMDG Code) · Ground (ADR / 49 CFR)

• State of charge: UN3480 limited to 30% of rated capacity; from Jan 1, 2026, the 30% limit also applies to lithium-ion batteries packed with equipment (UN3481) under IATA guidance · No SoC limit · No SoC limit
• Passenger carriage: Standalone lithium-ion (UN3480) forbidden on passenger aircraft; cargo aircraft only · Containerized cargo subject to stowage rules · Generally permitted with applicable packaging and marking
• Declaration: Shipper's Declaration for Dangerous Goods required for fully regulated sections · DG declaration required for fully regulated sections; Special Provision 188 shipments are simplified · Documentation per ADR / 49 CFR requirements
• Key packing rules: PI 965–970; 1.2 m drop test; operator variations (airlines and express carriers add their own restrictions) · SP 188 / SP 230 for small batteries; P903 for larger or fully regulated · ADR SP 188 / 49 CFR 173.185, with small-battery exceptions
• Damaged or defective: Forbidden on air transport; only with special permits or approved packaging outside standard rules · Dedicated packing instructions (e.g., P908); declared as damaged/defective · Restricted; follow national provisions

The 30% state-of-charge rule is a real operational constraint: your factory must discharge batteries to no more than 30% before packing for air freight, and a fully charged battery cannot be tendered by air under standard provisions without state-level approval. Build this into the production timeline rather than discovering it at the forwarder's warehouse, and confirm the specific airline's or express carrier's acceptance rules — carriers add restrictions on top of IATA.

For most China-to-overseas battery shipments, sea freight under the IMDG Code is the default: no state-of-charge constraint, fewer mode-specific restrictions, lower cost per unit. That is also where documentation discipline matters most, because that is where the volume moves.

What documents should you get from the factory — and how do you check them?

The test report is the foundation, but the document carriers actually request is the UN38.3 test summary. Since January 1, 2020, manufacturers and subsequent distributors must make this summary available to others in the supply chain. It must include the manufacturer and test lab names with contact details, a unique report identification number and date, the battery description (lithium-ion or lithium-metal, mass, Watt-hour rating or lithium content, physical description, model numbers), the list of tests with pass/fail results, the reference to the UN Manual of Tests and Criteria edition used, and the name and title of the responsible signatory.

Beyond the summary, a complete set for shipments from China typically includes the full test report, the safety data sheet (MSDS/SDS), a 1.2-meter drop test report for the packaging, and the cargo transport condition identification report for air or the classification report for sea — documents Chinese carriers and forwarders commonly require, usually applied for by the shipper or forwarder on the basis of the UN38.3 report and SDS.

China's dangerous-goods working group has recommended testing by qualified laboratories, with CNAS-accredited labs preferred for reports accepted at Chinese airports. A report from an unaccredited lab can be refused at acceptance regardless of its contents — ask which lab issued your supplier's report and confirm its accreditation.

Before committing to a shipment, verify the summary critically:

1. Match the model number to the exact battery you are buying — not a sibling product or last year's version.
2. Check every applicable test shows a pass, not just "tested."
3. Confirm cell and pack coverage — if you buy packs, the summary must cover the assembled battery, not only the cells inside.
4. Verify the lab's accreditation and the manual edition referenced.
5. Ask about design changes since the test date. New cells, a new BMS, or a new pack structure can invalidate the report.

Forged or borrowed test reports are a known problem in battery sourcing, and the mismatch usually hides in details — model numbers that don't match production, unreachable labs, unsigned summaries. A factory audit can confirm the report against the actual production line, the cells actually in use, and the issuing lab.

What are the importer's responsibilities?

Legal responsibility for dangerous-goods compliance sits with the shipper — the party offering the goods for transport. Buy on EXW or FOB terms and arrange freight yourself, and that is you, not the factory. Even on CIF or DDP terms, verify the paperwork: a failure at the port of loading becomes your delay and your cost.

In practical order, your responsibilities are to ensure the batteries have passed UN38.3 before booking anything; classify the shipment correctly (3480, 3481, 3090, or 3091); use compliant packaging and labeling; file accurate declarations with the forwarder and carrier, including the Shipper's Declaration for air freight where required; keep the test summary available for any carrier, forwarder, or regulator along the journey; and respect mode-specific restrictions such as air state-of-charge limits and cargo-aircraft-only rules. Personnel preparing lithium battery shipments are generally expected to be trained for their responsibilities — one more reason to use a forwarder or shipping and logistics partner experienced with dangerous goods rather than treating batteries as ordinary cargo.

Frequently asked questions

How long does UN38.3 testing take?

Typically a few weeks from sample submission to report, depending on the lab's queue and the battery's complexity. If any test fails, redesign and retesting add more time. Start early in your sourcing timeline — testing is not something to compress into the week before shipment.

Is there really no UN38.3 "certificate"?

Correct. UN38.3 produces a test report and a test summary, not a product certificate. When a supplier offers a "UN38.3 certificate," what you should receive is the lab test report plus the standardized summary. A certificate-style document without underlying test data and per-test results is incomplete — ask for the real documents.

Does UN38.3 testing expire?

The standard sets no validity period. A report stays tied to the specific battery design tested: unchanged design plus a credible lab means a valid report. What ends a report's usefulness is a design change — a new type requiring retesting — or a carrier or authority that refuses older reports.

Can one UN38.3 report cover several battery models?

Only if the models qualify as the same battery type under the testing rules — the same design, differing in ways that cannot affect test outcomes. Different capacities built from the same cells and protection design are sometimes grouped, but this is a technical judgment defined in the UN manual, not a supplier's marketing claim. Distinct designs need their own testing.

Does my supplier's report cover my private-label product?

If the product is the identical battery — same cells, same protection circuit, same pack design, same factory — the report normally applies, since testing covers the design, not the brand on the label. Anything structural that differs (different cells, added capacity, modified BMS) makes it a different type needing its own testing. Get this in writing before assuming coverage.

Who provides the UN38.3 test summary — the factory or a third party?

Manufacturers and subsequent distributors must make the summary available to the supply chain, and in practice your factory provides it, usually prepared by the testing lab. You should not need independent testing for an off-the-shelf battery design — but you must receive, check, and file the summary yourself.

Your 10-minute compliance check before booking freight

Apply this decision rule to every lithium battery order from China. Any "no" means stop and fix it before the goods move:

1. Do you hold a UN38.3 test summary matching the exact model, with a pass on every applicable test?
2. Can you name the correct UN number — 3480, 3481, 3090, or 3091 — and defend the classification?
3. Does the packaging provide short-circuit protection, full inner enclosure, and a 1.2 m drop-capable outer box, with the lithium battery mark and required labels?
4. If shipping by air, are batteries at no more than 30% state of charge, and is the booking on cargo aircraft where required?
5. Do you have the SDS and any carrier-required identification reports?
6. Is the lab accredited (CNAS for departures from China), and has the design changed since the test date?

Six yeses means your shipment rests on verified documentation rather than the supplier's assurance. Any no is a signal to pause — the failure mode here is a shipment refused at the airport, held at the port, or worse, a battery fire in transit. If you want help verifying test reports at the factory or coordinating DG-compliant shipping from China, write to hi@cnally.com and describe what you are importing.