Home Knowledge Understanding UN 38.3 Testing for Batteries: Why Is It Important

Understanding UN 38.3 Testing for Batteries: Why Is It Important

17/02/2025

Lithium and lithium-ion batteries are an integral part of everyday life due to their small size and long lifespan due to their high energy density. They are used in a wide range of industries including medical, consumer electronics, industrial applications and transportation, and these small and lightweight energy sources are a popular choice for manufacturers around the world because of their powerful capabilities.

Thermal Runaway and the Need for Testing

Lithium batteries contain lithium or lithium-ion metal. These components are highly reactive and unstable, offering high energy density. However, they can suffer from thermal runaway. This happens when a battery cell exceeds its melting point. The battery then produces hot gases, triggering a chain reaction with other cells. At this stage, batteries can leak, rupture, explode, or catch fire.

Lithium batteries use graphite as a cathode alongside lithium and lithium-ion metal oxide anodes. A protective layer, called a solid electrolyte interface (SEI), forms on the anode during initial charging. This layer slows the decomposition of the electrolyte. Unfortunately, high temperatures can break down the SEI, embedding lithium into the graphite. This interaction creates unwanted heat as negative reactions occur between the graphite, electrolyte, and polyvinylidene fluoride (PVDF) binder.

Due to these risks, lithium batteries are classified as Class 9 dangerous goods by the United Nations. They require the UN38.3 test, a recognized standard for ensuring lithium batteries are safely designed and manufactured for transport. Regular testing helps prevent dangerous incidents and ensures safe usage.

a thermal runaway lithium battery

Standard UN 38.3: Transport Testing of Lithium Batteries and Cells

Since lithium batteries are classified as Class 9 dangerous goods due to their fire hazard, they must meet the UN 38.3 standard for safe transport by air, sea, rail, or road. This standard applies to batteries transported alone or installed in equipment.

UN 38.3 governs all stages of battery transportation, from sub-suppliers to end-product manufacturers, and from manufacturers to distributors. It covers scenarios both inside and outside the product, including field use, returns, and instances of non-original packaging. As the use of lithium and lithium-ion batteries grows, manufacturers must understand these requirements.

Regulators and authorities worldwide have adopted UN 38.3 as essential for global market access. The protocol includes guidelines for identifying and classifying lithium batteries, testing and qualification requirements, design conditions, and packaging and shipping obligations.

UN38.3 Certification Testing Requirements

There are eight tests required for UN38.3 certification:

  • T1 - Altitude Simulation: Simulates low-pressure conditions for primary and secondary cells/batteries.
  • T2 - Thermal Test: Assesses integrity under extreme and rapid temperature changes for primary and secondary cells/batteries.
  • T3 - Vibration Test: Simulates vibrations encountered during transportation for primary and secondary cells/batteries.
  • T4 - Shock Test: Evaluates the battery's resilience to shocks and vibrations during transport for primary and secondary cells/batteries.
  • T5 - External Short Circuit Test: Simulates external short circuit conditions for primary and secondary cells/batteries.
  • T6 - Impact Test: Tests the cell casing's durability against impacts and crush scenarios for primary and secondary cells.
  • T7 - Overcharge Test: Simulates overcharging conditions for rechargeable batteries (secondary batteries).
  • T8 - Forced Discharge Test: Assesses performance under forced discharge conditions for primary and secondary cells.

Sample batteries undergo these test simulations to evaluate manufacturability and establish safe design parameters for battery components. The UN38.3 standard includes four classifications that determine the testing requirements based on the mode of transportation for the lithium-based batteries.

UN 3090 and UN 3480

This classification applies to all lithium and lithium-ion batteries shipped as cells or complete batteries outside of products. It also includes consignments of cells, modules, incomplete battery subassemblies, power packs, or power banks that are packaged separately, not inside a device. These separate packages may be in the same consignment or shipment container as the devices.

UN 3091 and UN 3481

This classification covers all lithium and lithium-ion batteries shipped inside devices. It also applies to batteries placed alongside the device in the same shipment package. For example, a shipment with a pre-installed battery in a device, along with two spare batteries in the same packaging, falls into this category.

Testing Requirements and Timetable

Lithium-based batteries undergoing UN 38.3 testing must have a specific number of packs sent to an approved independent testing laboratory. Typically, around 16 battery packs are submitted to generate a UN 38.3 report and summary detailing test results.

The test report spans about 10 pages and includes comprehensive technical details. The one-page summary focuses on 10 specific topics, featuring a sample description with the sample name, battery capacity, nominal voltage, charge current, limited charge voltage, maximum continuous charge current, cut-off voltage, end charge current, and maximum discharge current. It also lists the applicant's name and address, the battery manufacturer's details, the number of tested packs, the receiving date, and the test completion date.

The detailed report includes the standards used, test item specifics, methods and requirements, procedures, main test apparatus, test data, conclusions, and photos of the samples. The test summary is available to shippers upon request. The report serves as a certificate, applicable only to the original supplier of the battery or cell.

Testing typically takes 4 to 6 weeks. If the batteries or cells fail certification, this timeline may extend as they need redesigning and retesting.

Visit LiTime for Reliable LiFePO4 Lithium Battery

All LiTime LiFePO4 lithium batteries have passed the UN 38.3 testing, ensuring they meet the highest safety and performance standards for transport. Our batteries are designed for durability and efficiency, making them ideal for various applications, from renewable energy systems to electric vehicles.

At LiTime, we prioritize quality and reliability. Our LiFePO4 batteries offer excellent thermal stability, a longer lifespan, and enhanced safety compared to traditional lithium batteries. With a strong commitment to innovation, we continuously improve our products to meet the evolving needs of our customers.

Whether you need batteries for home energy storage, RV & Van life, marine trolling motors, or golf cart, LiTime provides a range of options tailored to your requirements. Our knowledgeable team is ready to assist you in selecting the right battery solution for your needs.

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