Battery Pack Certifications in Europe: IEC 62133, UN38.3, and What OEMs Need to Know

Most OEMs discover their certification requirements late, during CE marking, when a customer asks for test reports, or when a logistics provider refuses to ship. This post maps the key certifications for custom Li-Ion packs in Europe so that compliance is built into the design process, not retrofitted after.

The Certifications That Matter: An Overview

Each of these has a different scope, a different responsible party, and a different point in the development timeline when it becomes relevant. They are not interchangeable.

UN38.3: Transport Safety

UN38.3 is the baseline. Any Li-Ion cell or pack shipped commercially, by air, sea, or road, requires it.

The test series covers eight abuse conditions: altitude simulation, thermal cycling, vibration, shock, external short circuit, impact or crush, overcharge, and forced discharge. Each tests a different failure mode. The purpose is to demonstrate the cell or pack does not present a transport hazard under those conditions.

Several points matter for OEMs.

UN38.3 applies to the specific cell or pack design tested. It is not transferable. A new cell series, a new pack configuration, or a significant design change typically requires re-testing. A cell with UN38.3 coverage does not automatically extend that coverage to the pack assembly built around it.

This is the most common misunderstanding. If you are sourcing a custom pack, confirm that UN38.3 testing covers your specific pack configuration, not just the base cell. A tested cell inside an untested pack assembly is not compliant.

Always ask for the full test report. A certificate of compliance summarises a result. The test report shows the test conditions, the samples tested, and the specific pass/fail data for each test. If a problem arises later, during transport, customs, or a logistics audit, the full report is what matters.

IEC 62133-2: Product Safety for Li-Ion Packs

Where UN38.3 is about transport, IEC 62133-2 is about the pack as a product. It is the safety standard for portable sealed secondary lithium cells and batteries. Part 2 covers lithium systems.

It evaluates electrical, mechanical, and environmental safety. Tests include continuous charge, abnormal charging, external short circuit, drop, vibration, and temperature exposure. Unlike UN38.3, it assesses the pack as an end product, closer to a product safety certification than a transport classification.

Most portable Li-Ion products entering CE-marked consumer or commercial devices require it. Beyond legal obligation, it appears in customer contracts and procurement specifications. Retail distribution channels and B2B supply chains often require it as a condition of doing business, regardless of regulatory mandate.

IEC 62133 coverage is not universal across all cell types. Coverage depends on whether the specific cell has been tested and certified. SA17, SA08, SA110, and the Drone Series A carry IEC 62133-2 certification. SA11 does not. If your application requires IEC 62133, cell selection has to account for this. Do not assume coverage. Confirm it at the specification stage for your specific cell.

Some sectors have their own standards that replace or augment IEC 62133. IEC 60601 applies to medical devices. DO-160 and MIL-STD-810 apply to aerospace and defence. If you are building into a regulated sector, establish which standard governs your end product early, before cell selection and BMS architecture are locked in. Changing standard requirements after tooling is a costly problem.

The pack manufacturer typically holds the IEC 62133 test report. Ask for it when you are defining the specification, not when you are approaching market entry.

CE Marking and the Battery Pack

CE marking is not a certification issued by a third party. It is the manufacturer’s declaration that the product conforms to all applicable EU directives. The OEM makes that declaration. The OEM owns the responsibility.

For battery packs, whether sold as standalone products or integrated into a larger system, three directives are typically relevant.

The Low Voltage Directive (LVD 2014/35/EU) applies to electrical equipment. Most battery packs fall within its scope. It requires that the equipment be safe during normal operation and reasonably foreseeable misuse.

The EMC Directive (2014/30/EU) is relevant when the pack contains active electronics, a BMS with communication interfaces, for example. If the pack can generate, or be affected by, electromagnetic interference, EMC applies.

RoHS restricts hazardous substances in electronic equipment. It applies to BMS components and associated electronics.

The practical implication: if you integrate a custom battery pack into a CE-marked product, you are responsible for ensuring the pack contributes to your CE declaration, not against it. That means getting supplier documentation, test reports, declarations of conformity, material declarations, at the design stage. Waiting until the pre-production phase to collect documentation creates delays that affect your launch date.

The pack supplier provides documentation. The OEM uses it. Both parties need to understand what is needed and when.

ADR: Road Transport in Europe

ADR is the European Agreement concerning the International Carriage of Dangerous Goods by Road. Li-Ion batteries are classified as Class 9 dangerous goods.

The thresholds that trigger full ADR compliance are: cells above 20 Wh or batteries above 100 Wh, when shipped in quantity. Industrial packs for AGV, robotics, or drone applications typically exceed these thresholds.

ADR requirements include proper packaging, hazard labelling, transport documentation, and, in some cases, driver training and vehicle marking. The specifics depend on total quantity being shipped, mode of transport, and whether the batteries are packed with equipment or shipped as standalone goods.

Your pack manufacturer should handle outbound shipment documentation for packs they ship to you. The more important question for OEMs is your own logistics chain. If you are importing packs from outside the EU, or transporting assembled products containing Li-Ion packs to customers, you need to understand ADR obligations in your own operations. Logistics providers will ask. Some will refuse a consignment if documentation is not in order.

EU Battery Regulation 2023/1542

This is the most significant regulatory change for the battery supply chain in recent years. It is broad, phased, and still evolving. Worth flagging here, not to cover it fully, but to make clear it is already in force.

The regulation applies to all batteries placed on the EU market: portable, industrial, EV, and SLI. Requirements include carbon footprint declarations, recycled content targets, due diligence on raw materials, labelling, and end-of-life take-back obligations.

The provision most relevant to OEMs building custom packs: industrial batteries above 2 kWh will require a digital battery passport starting in 2026. The battery passport is a structured dataset that tracks the battery’s composition, performance, carbon footprint, and supply chain information across its lifecycle.

OEMs buying custom packs for EU-sold products will need their battery supplier to provide the data that feeds into that passport. This is not a future concern. If you are building a product that will be in production in 2026 or beyond, your supplier’s compliance roadmap is a procurement consideration today. Ask about it now.

Timeline: When to Start

The most common mistake is treating certification as a final-stage task. It is not. Certification is a design input.

IEC 62133-2 testing requires physical samples and lab time. Six to twelve weeks is realistic. Discovering this requirement at the pre-production stage, when your launch schedule is fixed, means either a delayed launch or shipping without certification.

The other mistake is assuming certification is entirely the supplier’s problem. The supplier provides test reports and declarations. The OEM owns the CE declaration. Both parties have obligations, and those obligations have to be understood at the start of the project, not negotiated at the end.

Décisions clés : résumé

• UN38.3 is required for any Li-Ion pack shipped commercially. Confirm it covers your specific pack configuration, not just the base cell. Get the full test report.
• IEC 62133-2 is required for most EU market entry scenarios. Coverage varies by cell, SA11 does not carry IEC 62133. Ask for the test report at specification stage.
• CE marking is the OEM’s responsibility. The pack supplier provides documentation that feeds into the declaration. Collect it at design stage, not pre-production.
• ADR applies to road transport of packs above threshold Wh. Understand the obligations in your own logistics chain, not just your supplier’s.
• EU Battery Regulation 2023/1542 is live and phasing in. Industrial batteries above 2 kWh need a digital battery passport from 2026. Start discussing your supplier’s compliance roadmap now.
• Start at design kick-off. Certification retrofitted late adds cost, delays launch, and creates risk. Built in from the start, it is a manageable engineering input.

Dan-Tech Energy designs and builds custom Li-Ion battery packs for OEM applications across Europe. Use the ToolBox to define your application and get a straight answer on what your pack needs. Explore the full range at our Li-Ion battery pack catalog.