UN 38.3 – Transport testing for lithium and sodium-ion batteries
UN 38.3 is the central testing standard for the transport of lithium metal, lithium-ion and sodium-ion batteries. The standard is part of the UN Manual of Tests and Criteria and defines eight test procedures (T.1 to T.8) that batteries must pass before transport. The test results are documented in a test summary. Without a passed UN 38.3 test, lithium and sodium-ion batteries may not be transported by air, sea, road or rail.
| Aspect | Details |
|---|---|
| Scope | Lithium metal, lithium-ion and sodium-ion cells and batteries for the transport of dangerous goods |
| Test subject | Cells and batteries (lithium metal, lithium-ion, sodium-ion with organic electrolyte) |
| Test scope | 8 tests: altitude simulation, thermal cycling, vibration, shock, external short circuit, impact/crush, overcharge, forced discharge |
| Typical duration | 4 - 6 weeks |
| Certification document | Test summary in accordance with Section 38.3.5 with ten mandatory data points |
| Current version | 8th revised edition (2023) with Amendment 1 (2025) |
| Related standards | IEC 62133-2, UL 1642, ADR Chapter 3.3 (SP 188/230), IATA DGR, IMDG Code |
What UN 38.3 covers
UN 38.3 defines standardised test procedures for classifying lithium metal, lithium-ion and sodium-ion batteries for transport. The standard comprises eight tests (T.1 to T.8) that simulate mechanical, thermal and electrical stresses.
The test procedures in detail:
- T.1 Altitude simulation: simulation of reduced pressure during air transport (11.6 kPa, minimum 6 hours)
- T.2 Thermal cycling: cyclic temperature exposure between −40 °C and +75 °C
- T.3 Vibration: frequency- and acceleration-controlled vibration exposure
- T.4 Shock: mechanical shock exposure (half-sine pulse)
- T.5 External short circuit: short circuit at 55 °C ± 2 °C with resistance below 0.1 Ω
- T.6 Impact/crush: mechanical damage by impact (cells) or crush (batteries)
- T.7 Overcharge: charging at twice the maximum current and twice the maximum voltage (rechargeable batteries only)
- T.8 Forced discharge: discharge of a single cell in an assembly against the other cells
In addition, UN 38.3 defines the requirements for the test summary. This document contains ten mandatory data points and serves as proof of compliance for transport.
Where UN 38.3 applies – and where it does not
UN 38.3 applies to all lithium metal, lithium-ion and sodium-ion cells and batteries transported as dangerous goods. The standard differentiates by battery type, form factor and transport mode.
The test assignment distinguishes between primary lithium metal cells and batteries, rechargeable lithium-ion cells and batteries, and sodium-ion cells and batteries with organic electrolyte (since Amendment 1, 2025).
Exceptions apply in the following cases:
- Component cells not transported separately: only T.6 and T.8 required
- Sodium-ion cells and batteries: T.8 (forced discharge) not required
- Integral cells and batteries: testing in installed condition possible
- Assembled batteries exceeding 500 g lithium content or exceeding 6,200 Wh: no testing required if protection is demonstrated at cell level
The exceptions are each subject to specific conditions. The responsible testing laboratory provides binding information.
When you need UN 38.3
UN 38.3 is required whenever lithium or sodium-ion batteries are transported. The testing obligation arises from international dangerous goods regulations.
Typical scenarios:
- Air freight transport: IATA Dangerous Goods Regulations (DGR) require a passed UN 38.3 test
- Sea freight transport: IMDG Code references UN 38.3
- Road transport: ADR (Europe) and DOT (USA) require UN 38.3
- Rail transport: RID references UN 38.3
Special provisions 188 and 230 of the UN Model Regulations define the testing obligation. Without a valid test summary, compliant transport is not possible.
Since Amendment 1 (2025), the testing obligation also applies to sodium-ion batteries with organic electrolyte.
Where UN 38.3 applies
UN 38.3 applies worldwide. The standard is part of the UN Manual of Tests and Criteria and is recognised by all international transport organisations.
The UN regulations are implemented through regional and modal regulations:
- Air transport: ICAO Technical Instructions, implemented through IATA DGR
- Sea transport: IMDG Code of the International Maritime Organization (IMO)
- Road transport: ADR (Europe), DOT 49 CFR (USA), TDG (Canada)
- Rail transport: RID (Europe)
Test results are mutually recognised internationally. A UN 38.3 test report is valid across all transport modes and regions.
When UN 38.3 becomes relevant in the product lifecycle
UN 38.3 becomes relevant at several stages of the product lifecycle.
Development: The UN 38.3 test is a type test. It is conducted on battery samples that correspond to the later series products. Testing should be planned already during the development phase.
Production: After a passed type test, the test report applies to all identical units. Changes to cell chemistry, housing or BMS require a new test.
Distribution and transport: The test summary must be available for every shipment. Without this document, compliant dispatch is not possible.
Repair and remanufacturing: Amendment 1 (2025) introduces a re-testing obligation. If non-original parts are used during repair or remanufacturing, renewed testing is required.
How UN 38.3 testing works
The UN 38.3 test follows a defined sequence. The battery samples undergo tests in a specified order. Different battery samples are used depending on the test procedure.
Test Overview
Battery sample selection and conditioning
The number of battery samples depends on battery type and test procedure. Tests T.1 to T.5 are conducted sequentially on the same battery samples. Separate, untested battery samples are used for T.6 and T.8. All battery samples are conditioned at 20 °C ± 5 °C before testing begins.
Sequential tests T.1 to T.5
The first five tests are conducted consecutively on the same battery samples. Altitude simulation (T.1) tests behaviour under reduced air pressure. Thermal cycling (T.2) simulates extreme climate conditions. Vibration (T.3) and shock (T.4) test mechanical durability. External short circuit (T.5) tests electrical safety.
Separate tests T.6, T.7 and T.8
T.6 (impact/crush) and T.8 (forced discharge) are conducted on undamaged battery samples that have not previously undergone tests T.1 to T.5. T.7 (overcharge) is conducted on rechargeable batteries only. Sodium-ion batteries are exempt from T.8.
Pass criteria and documentation
Each test has defined pass criteria. Typical requirements: no mass loss exceeding defined thresholds, no flame formation for more than ten minutes, no gas release exceeding limit values, voltage after test within defined tolerances. The results are documented in the test summary in accordance with Section 38.3.5.
Frequently asked questions about UN 38.3
Which batteries require testing
All lithium metal, lithium-ion and sodium-ion cells and batteries that are transported require a passed UN 38.3 test. Since Amendment 1 (2025), the testing obligation also applies to sodium-ion batteries with organic electrolyte. Exceptions exist for certain component cells and batteries exceeding defined thresholds. The responsible testing laboratory provides binding information on the exact requirements.
Definition of a new type
A new type exists when safety-relevant characteristics of the cell or battery change. This includes changes to cell chemistry, cell construction, housing design, BMS or maximum capacity. In these cases, renewed testing under UN 38.3 is required. Minor changes that do not affect safety generally do not require re-testing. The responsible testing laboratory assesses whether a change constitutes a new type.
Validity of the test report
The UN 38.3 test report has no formal expiration date. It remains valid as long as the design of the tested cell or battery remains unchanged. Changes to cell chemistry, housing, BMS or other safety-relevant components require a new test. Some authorities may require more recent test reports. The responsible testing laboratory provides binding information.
Changes introduced by Amendment 1
Amendment 1 extends the scope of UN 38.3 to sodium-ion batteries with organic electrolyte. Additionally, a re-testing obligation is introduced for batteries that are repaired or remanufactured using non-original parts. The test assignment table in Section 38.3.3 has been updated accordingly to include sodium-ion cells.
VRI supports you in preparing and conducting tests in accordance with UN 38.3. Contact us for an initial consultation.
Ralf Isermeyer
Geschäftsführer / CEO
The information on this page is intended for general guidance. It does not replace consultation of the official standard documents.
The current version of UN 38.3 (currently: 8th revised edition, 2023, with Amendment 1, 2025) is authoritative in all cases.
Last updated: February 2026 | Basis: UN 38.3, 8th revised edition (2023) with Amendment 1 (2025) | Source: VRI GmbH