Putting a lithium battery into a product looks like an engineering decision like any other: pick the chemistry, size the capacity, move on. In compliance terms it is not. It is the single decision that opens the most regulatory fronts at once, and it is almost always discovered too late.
Because it does not open one front. It opens three, and they are independent of each other: the conformity of the cell, that of the finished product, and transport. Each has its own legislation, its own testing and its own paperwork, and satisfying one covers you for none of the others.
And there is a recent date worth checking: since 18 August 2026 the labelling requirements of Article 13 of the Battery Regulation are enforceable. This is not a future deadline — it is already in force.
Table of contents
Not one more requirement: three separate fronts
The usual confusion is treating the battery as just another line on the bill of materials. It helps to separate things from the start:
- The cell or pack as a product. It has its own European legislation, its own conformity assessment and its own marking.
- The electrical and chemical safety of the cell. Demonstrated through product standards, typically the IEC 62133 series.
- Transport. A world of its own, governed by dangerous goods rules, with nothing to do with CE marking.
On top of those three sits everything that already applied to your product: electromagnetic compatibility, electrical safety and, if it carries a radio, the corresponding directive. We break that down in our general guide to CE marking costs for electronic products.
The Battery Regulation (EU) 2023/1542
What it replaces and what it covers
Regulation (EU) 2023/1542 repeals the old Directive 2006/66/EC and changes the approach entirely: it moves from regulating mostly waste to regulating the whole lifecycle, from design and materials through to recycling.
The part that matters for product developers: every battery placed on the EU market must go through a conformity assessment procedure and carry the CE marking, together with its declaration of conformity, which must be kept for ten years.
Labelling enforceable since 18 August 2026
This is the milestone that has already taken effect. From that date, cells and batteries must carry a label with the general information set out in Annex VI Part A: manufacturer details, battery category, chemical composition, hazardous substances present and critical raw materials, among other items.
There are also type-specific requirements: portable rechargeable batteries and those for light means of transport must state their capacity, and portable non-rechargeable ones their minimum average duration in typical applications.
This affects the physical design, not just the paperwork. That information has to fit, be legible and be indelible. In a compact product with an integrated battery, where the label goes is an enclosure decision — and it arrives far too late once the tooling is cut.
Separate collection and due diligence
Since 18 August 2025 the separate collection symbol on all cells and batteries and the supply chain due diligence obligations have applied. The latter means being able to document where materials come from, which is solved by requiring it from your cell supplier contractually, not by improvising afterwards.
The battery passport
From 18 February 2027 a battery passport becomes mandatory for electric vehicle batteries, light means of transport batteries and industrial batteries above 2 kWh: a digital record carrying manufacturer identification, material composition, carbon footprint and recycled content.
For a consumer electronic product with a small cell, this does not apply. It is still worth knowing if the product might scale toward larger packs.
Cell safety: IEC 62133
IEC 62133 is the international safety standard for rechargeable cells and batteries used in portable equipment. It verifies electrical, mechanical and chemical behaviour under abuse conditions: overcharge, short circuit, crush, extreme temperatures.
If you buy cells from a serious manufacturer, they will normally already be tested to this standard and the report will come with them. That document is one of the pieces that goes into your technical file, and its absence is one of the most frequent reasons a file ends up incomplete.
Transport: UN 38.3 and the 100 Wh threshold
This is the front that surprises people most, because it has nothing to do with CE marking and can still block your business.
UN 38.3 is the transport test for lithium cells and batteries. It simulates shipping conditions through eight tests: simulated altitude, thermal cycling, vibration, shock, external short circuit, impact or crush, overcharge and forced discharge. Since 1 January 2020, manufacturers and distributors must be able to provide a detailed summary of the results.
Without that document you will not, in practice, ship the product: neither freight forwarders nor airlines will accept it.
The 100 Wh threshold. Above that energy, lithium batteries fall into class 9 dangerous goods, with far stricter packaging, labelling and transport documentation requirements and serious air freight restrictions. If your design sits near that figure, it is worth checking whether staying below it pays off.
What applies to the finished product
EMC, low voltage and radio
Everything you already knew still applies. The battery exempts you from nothing: the product still has to meet electromagnetic compatibility and, if it carries a radio, the corresponding directive and its cybersecurity requirements.
In fact, the battery adds EMC problems of its own. The charging converter is a switching supply inside your product, and charging circuits are a common cause of conducted emissions above the limits. It is one more reason to approach PCB design with testing in mind from the start.
What documentation your cell supplier owes you
Before committing to a supplier, request and keep:
- the UN 38.3 test report and its results summary,
- an IEC 62133 report or certificate,
- the declaration of conformity for the cell or pack,
- the safety data sheet and full technical specification,
- and the information you need to satisfy due diligence on materials.
If a supplier resists handing any of this over, that is a signal. And if you buy through an intermediary, remember that whoever places the product on the European market takes on the manufacturer's obligations.
Common mistakes with batteries
- Leaving labelling to the end. The mandatory information has to physically fit and be indelible. With the tooling closed, the options are all bad.
- Assuming a certified cell certifies the product. They are different assessments with different scopes.
- Switching cell supplier mid-production without checking whether the new cell carries the same documentation. That is a change with technical file consequences.
- Designing above 100 Wh without needing to, and discovering the logistics overhead when there is no margin left.
- Changing the charge profile in firmware after testing: charge management is a safety function.
- Not planning end of life. Collection, recycling and registration are real obligations, not a detail.
How we approach it at RobotUNO
As with everything compliance-related: we are not an accredited laboratory or a notified body. We do not issue battery certificates and we do not sign declarations of conformity.
What we do is the work that comes before:
- Choose chemistry, format and supplier with an eye on what documentation actually comes with the cell.
- Size the pack knowing where the thresholds that change the transport regime sit.
- Design the charging and protection electronics, and the firmware governing them, for what they are: a safety function.
- Reserve space in the enclosure for the labelling the regulation demands.
- Gather and organise cell and pack documentation inside the product's technical file.
It is part of the move to production described in industrialization and mass manufacturing, and of any electronic product development meant to run without a cable.
If you take one idea away: the battery is not a component you pick at the end on price and capacity. It is a regulatory decision with consequences for the enclosure, logistics, firmware and documentation. The earlier it is made, the cheaper it is.
Frequently asked questions
Does the battery need CE marking, or the product?
Both, and they are separate processes. The battery has its own conformity assessment procedure and its own marking under Regulation (EU) 2023/1542. The finished product has its own under whichever directives apply to it. Buying compliant cells does not make your product compliant.
What is UN 38.3 and when do I need it?
It is the transport test for lithium cells and batteries: it simulates shipping conditions (altitude, thermal cycling, vibration, impact, short circuit, overcharge). Since January 2020 you must be able to provide a test summary. Without it you effectively cannot ship the product by air or sea.
What changed on 18 August 2026?
The labelling requirements of Article 13 of the Battery Regulation became applicable: the label must carry the general information in Annex VI Part A and, for portable rechargeable batteries, capacity information. It is enforceable now, not a future deadline.
Is it enough for my supplier to say the cell is certified?
Saying it is not enough. You need the documents: the UN 38.3 report, an IEC 62133 report or certificate, and the cell's declaration of conformity. If your supplier will not hand them over, assume they do not exist and budget for obtaining them yourself.
What changes above 100 Wh?
Lithium batteries above 100 Wh are treated as class 9 dangerous goods, with much stricter packaging, labelling and transport documentation requirements, plus air freight restrictions. It is a threshold worth keeping in mind when sizing the pack.
Does your product have a battery and a market date?
Tell us which cell you are considering and where the design stands. We will tell you what documentation you are going to need and which decisions are worth settling first.
