Ensuring Safe Lithium-ion Battery Transportation：Key FAQs & Certification Requirements Explained --- Updated Regularly

Q1: Why can't lithium batteries be shipped casually by courier or air freight? What certifications are required?
A1: Lithium batteries pose a thermal runaway risk and may cause fires or explosions during transportation. The International Air Transport Association (IATA) and the International Civil Aviation Organization (ICAO) classify them as Class 9 dangerous goods, requiring strict compliance with packaging, labeling, documentation, and transportation restrictions.

Q2. What is the difference between a cell and a battery?

A cell is a single encased electrochemical unit consisting of one positive and one negative electrode that exhibits a voltage differential across the two terminals. A battery is two or more cells electrically connected. A single cell battery is considered a cell and not a battery for the purposes of the limitations set out in the DGR.

Q3. Are all lithium and sodium ion batteries classified as dangerous goods (when

transported by air/ when transported as air cargo)?

All lithium and sodium ion batteries are classified as dangerous goods due to the presence of the threat of thermal runaway and are subject to the requirements of the DGR. Although some lithium and sodium ion batteries are eligible for transportation as Section II and exempted from certain labelling, packing and documentation requirements, these batteries are still regulated as a dangerous goods commodity, and subject to all other requirements, including dangerous goods reporting.

Q4: What are the common certifications required for the transportation of lithium batteries?
The transportation of lithium-ion batteries packed by themselves (UN 3480) requires the state of charge (SoC) to be no more than 30% of rated capacity. Cells or batteries with an SoC exceeding 30% may only be shipped with approval from both the State of Origin and the State of the Operator under Special Provision A331, and are prohibited on passenger aircraft unless authorized by relevant authorities in accordance with Special Provision A201.

Common certifications for lithium battery transport typically include UN38.3 test reports and Material Safety Data Sheets (SDS/MSDS). Requirements differ by mode of transport: air shipment mandates an air transport test report for lithium batteries, while sea freight requires a sea transport test report.

With 17 years of research and industry experience, Keeppower provides professional certification consulting services as a leading lithium battery manufacturer. We offer end-to-end support—from design, sampling, and mass production of lithium cells and battery packs, to certification acquisition and final delivery. Our team delivers timely certification guidance, explores flexible shipping solutions, and is committed to providing high-quality, cost-effective services that save both time and resources for our customers.

Q5. What is the Watt-hour (Wh) rating of a lithium-ion battery and why is it important?

The Watt-hour (Wh) rating is a key measure of the total energy capacity of a lithium-ion battery. It is calculated using the formula: Wh = Nominal Voltage (V) × Rated Capacity (Ah). If the capacity is given in milliampere-hours (mAh), divide by 1,000 to convert to ampere-hours (Ah).

This rating is especially important in air transport regulation, as it is a core classification criterion under International Air Transport Association (IATA) Dangerous Goods Regulations. The Wh rating determines whether a battery is classified under Section I (high energy) or Section II (low energy) rules, which in turn affects:

Packaging requirements– whether UN-certified packaging is mandatory
Labeling– whether the lithium battery handling mark must be applied
Shipping restrictions– such as prohibitions on transport aboard passenger aircraft

Key Classification Thresholds:

Cell:20 Wh threshold
Battery (multi-cell):100 Wh threshold
≤ 20 Wh per cellor ≤ 100 Wh per battery:
Generally qualifies for Section II (less restrictive) requirements, which may include exemptions from UN-certified packaging and certain markings.
> 20 Wh per cellor > 100 Wh per battery:
Falls under the fully regulated Section I category, requiring:
- UN-certified packaging
- Prohibition on transport as cargo on passenger aircraft (P15)
- A Dangerous Goods Declaration (DGD)

Q6. What constitutes a design change requiring renewed design type testing?

The following provisions are taken from the 8th revised edition of the UN Manual of Tests and Criteria, paragraph 38.3.2.2. A cell or battery that differs from a tested design by:

For primary cells and batteries, a change of more than 0.1 g or 20% by mass, whichever is greater, to the cathode, to the anode, or to the electrolyte;
For rechargeable cells and batteries, a change in Watt-hours of more than 20% or an increase in voltage of more than 20%;
A change that would materially affect the test results shall be considered a new type and shall be subjected to the required tests.

Note: the type of change that might be considered to differ from a tested type, such that it might lead to a failure of any of the test results, may include, but is not limited to:

A change in the material of the anode, the cathode, the separator or the electrolyte;
A change of protective devices, including the hardware and software;
A change of safety design in cells or batteries, such as a venting valve;
A change in the number of component cells;
A change in connection mode of component cells;
For batteries which are to be tested according to T.4 with a peak acceleration less than 150 gn, a change in the mass which could adversely impact the result of the T.4 test and lead to a failure.