If your product contains a lithium battery — even a coin cell — UN38.3 is unavoidable when exporting. This article covers what is tested, the pass criteria, the documents required, and the common pitfalls.
What UN38.3 Is, and Its Legal Basis
UN38.3 comes from Section 38.3 of Part III of the UN Manual of Tests and Criteria. It sets transport-safety test requirements for lithium metal and lithium-ion batteries, and is referenced by air (IATA Dangerous Goods Regulations), sea (IMDG), road and rail rules. The core idea is to make sure the battery will not catch fire or explode under the stresses of transport — altitude pressure changes, temperature extremes, vibration and impact. Note that it addresses transport safety, not safety in use, and does not determine whether the product can be sold in the destination country.
The Eight Tests in Detail
- T1 Altitude simulation: pressure reduced to 11.6 kPa or below for at least 6 hours, simulating a high-altitude cargo hold
- T2 Thermal test: cycling between -40°C and 72°C, at least 6 hours at each extreme, for 10 cycles
- T3 Vibration: simulating sustained vibration in transit
- T4 Shock: a half-sine shock pulse simulating handling impacts
- T5 External short circuit: shorting the battery externally at 55°C with external resistance below 0.1 ohm
- T6 Impact/crush: impact test for cylindrical cells; crush test for prismatic and pouch cells
- T7 Overcharge: charging at the specified current (generally twice the manufacturer's recommended maximum) for 24 hours
- T8 Forced discharge: forcing the cell into over-discharge
T1 through T5 are normally run in sequence on the same samples, while T6, T7 and T8 use separate samples. Pass criteria generally require no leakage, venting, disassembly, rupture or fire, and an open-circuit voltage of at least 90% of the pre-test value after T1-T5. Sample quantities and applicability follow the current edition of the UN Manual and the lab's test plan.
Who Needs This Testing
- Producers of the cells and batteries themselves
- Exporters of finished goods with built-in lithium batteries (power banks, power tools, Bluetooth devices and so on)
- All related products shipped by air, sea or land
Required Documents: Test Report and Test Summary
UN38.3 requires more than a test report. A Test Summary is also needed — since 2020, air transport rules require manufacturers and subsequent distributors to make it available. It includes manufacturer details, battery model and specifications, test laboratory information and test results. Freight forwarders and airlines also commonly ask for a transport classification document, documents on dangerous-goods packaging performance, and an MSDS (safety data sheet).
Key Numbers Affecting Transport Restrictions
- Watt-hour (Wh) rating: a lithium-ion battery's Wh rating determines its transport classification. Batteries above 100Wh face notably tighter limits; 100-160Wh generally needs airline approval, and above 160Wh generally cannot be carried by passengers
- State of charge: lithium-ion batteries shipped alone (UN3480) are generally required to be at no more than 30% state of charge by air
- UN numbers: batteries shipped alone are UN3480; those packed with or contained in equipment are UN3481/UN3091 and so on, each with its own packing instruction and restrictions
Specific limits follow the latest IATA DGR and carrier policies — confirm with your forwarder before shipping.
Common Pitfalls
Pitfall 1: The cell supplier has a report, so the finished product needn't be tested. A cell's UN38.3 report only proves the cell itself complies. If you assemble a pack (adding a protection board, casing or leads), the whole battery pack generally needs to be re-tested or at least covered by a compliance document.
Pitfall 2: A report is valid forever. Most logistics providers and platforms ask for a recent report, and a change in battery model, assembly or cell supplier also requires retesting.
Pitfall 3: Small batteries needn't be tested. Regardless of capacity, any lithium battery product in principle needs to meet UN38.3; only the transport restrictions (passenger aircraft, cargo aircraft, sea) differ by energy level.
Pitfall 4: Having only the test report and no test summary. Many shipments are held at airports or by forwarders because the test summary is missing or incomplete.
Cost and Timeline Reference (for budget planning only, not a quote)
- A single cell or battery model: the full eight-test programme typically takes about 2-3 weeks, with a sizeable sample quantity that needs to be ready in advance
- Multi-specification battery series: a representative model may be tested, but whether it covers the range depends on the lab and the rules
- If a first test fails, add time for rectification and retesting
Pricing depends on battery type (cell or pack), quantity and specification — send the battery datasheet for an assessment.
If you're unsure where your product sits or which report you need, contact us and we'll help sort it out, including checking that your test summary and other documents are complete.