What exactly does ‘indelible’ mean in the context of the EU Battery Regulation?
One word. Four syllables. And it is currently keeping compliance managers, production engineers and regulatory teams at battery manufacturers across Europe awake at night. Because battery labelling is about to become more complex.
Indelible.
Google defines the word as “something so profound or lasting that it cannot be eliminated, forgotten or undone.”
Article 13(7) of Regulation (EU) 2023/1542 stipulates that labels and QR codes must be “visibly, legibly and indelibly printed or embossed on the battery”. The word appears repeatedly in the Regulation. The carbon footprint label must be indelible. The CE marking must be indelible. The QR code leading to the battery passport must be indelible. The symbol for separate collection must be indelible.
However, the regulation does not define ‘indelible’ even once.
This is no accident. It is a deliberate choice made by the legislator. Anyone who understands why the drafters chose this word and what it means in practice will recognise the difference between genuine compliance and costly wishful thinking.
Why the regulation deliberately uses this word
EU product legislation has a long tradition of using performance-based wording rather than prescriptive technical specifications. The drafters of Regulation (EU) 2023/1542 did not mandate laser marking. They did not ban adhesive labels. They wrote ‘indelible’ — and left it to manufacturers and market surveillance authorities to determine what that means for each battery type, each application and each life cycle.
The word derives from the Latin indelebilis — meaning ‘that which cannot be erased or removed’. In the context of the Battery Regulation, the intention is clear, even if the definition is lacking: the marking must outlast the battery’s service life. It must still be legible at the end of that service life. It must withstand all the conditions to which the battery is exposed during use.
From 18 August 2026, batteries must bear comprehensive labelling. This must include the place of manufacture, battery category, weight and information on all hazardous substances except mercury, cadmium and lead. From 18 February 2027, all electric vehicle and industrial batteries over 2 kWh placed on the market in the EU will require a digital battery passport. This passport will be accessible via a QR code — and the QR code must be printed or engraved on the battery.
Both deadlines are fast approaching. Neither allows for the luxury of a wait-and-see approach.
Production of battery cells
What ‘indelible’ means in practice: the decisive test
Think about where EV battery packs and industrial batteries are actually used. They operate at high temperatures. They are exposed to vibrations, chemicals, cleaning agents and moisture for years on end. In recycling plants, they are handled roughly, sorted mechanically and processed on a large scale.
A marking is only truly indelible if it withstands all of this — whilst remaining visible, legible and intact. The Regulation expressly states that the purpose of the marking requirement is to ensure traceability throughout the battery’s entire life cycle, including recycling and end-of-life disposal.
Article 13 stipulates that all batteries placed on the market in the EU must bear clear, legible and indelible markings. Manufacturers must ensure that these markings remain visible under normal conditions of use throughout the battery’s lifetime.
It is precisely this phrase — ‘throughout the battery’s entire service life’ — that is the key benchmark. Not at the time of manufacture. Not for the first year of operation. Throughout the entire service life.
What fails this test
Adhesive labels are the most common method today. Many manufacturers apply printed labels to the battery casing — they are quick to apply, easy to change between production runs, and have been a familiar feature of product labelling for decades.
Under the EU Battery Regulation, adhesive labels have a fundamental problem: they can be removed.
To be more precise: they come off. Adhesive labels peel away. In damp environments, they lift at the corners. They deteriorate when subjected to thermal cycling. Chemical influences — including cleaning agents used in industrial battery maintenance — attack the adhesive. Over the ten-year operational life of an industrial battery or the full lifespan of an EV battery pack, it cannot be reliably guaranteed that an adhesive label applied at the manufacturing site will still be visible and legible at the end of that period.
The rule is clear: labels and markings must be visible, legible and indelible — and must be affixed directly to the battery. If a label can be physically separated from the battery, it cannot, strictly speaking, be indelible.
The market surveillance authorities of the EU Member States enforce these regulations. The Regulation empowers them to require recalls and withdrawals in the event of identified infringements. Incorrect or misleading battery labelling can trigger product recalls, withdrawals, fines and removal from the market. Labelling issues are often considered an infringement — even if the battery itself is technically safe.
A label that comes away from the battery at a recycling plant is, by definition, a failure of the labelling system.
What meets the requirements: Why laser marking works
Laser marking works differently from any surface-application process. A laser beam — in the case of fibre laser marking, a focused infrared beam — acts directly on the surface material of the battery casing. The marking is not applied to the surface; it is created within the surface itself, through controlled thermal or photochemical changes in the substrate.
There is nothing that can come loose. Nothing that can lift up. Nothing that can disintegrate independently of the battery casing itself.
A laser-marked label on an aluminium battery casing will remain on that casing for as long as the casing exists. It withstands the same temperatures, chemicals, vibrations and handling as the battery. It cannot be separated from the component it identifies — without destroying the component itself.
That is exactly what ‘non-removable’ means. And that is exactly what the Battery Regulation requires.
For EV batteries and industrial batteries with a capacity of over 2 kWh — the battery categories subject to the regulation’s most stringent compliance requirements — laser marking offers further practical advantages:
Marking speed: Modern fibre laser systems mark at production speed. Data Matrix codes, serial numbers, CE marks and carbon footprint classifications — all in a single pass, within seconds, without stopping the production line.
Quality of Data Matrix and QR codes: The QR code must be visible, legible and indelible on the battery. Laser-marked Data Matrix codes and QR codes achieve the contrast and resolution required for reliable scanning throughout the entire life cycle. A printed or adhesive QR code that becomes worn over the years cannot be reliably read by the automated scanning systems at a recycling plant. This renders the entire purpose of the battery passport meaningless.
Integration of traceability: Every laser-marked identification can be recorded directly at the point of marking. This creates a direct link between the physical battery and its digital entry in the battery passport. This is precisely the basis of the traceability chain that the regulation is intended to establish.
Material compatibility: Fibre laser marking works on aluminium, steel, nickel-plated surfaces and many polymer housings used in battery module construction. MOPA laser systems offer additional control over marking contrast and depth — particularly useful for anodised aluminium and other surface-treated materials commonly found in battery housing design.
A close-up view of battery cells
The alternative solution for packaging: what it is and what it isn’t
The Regulation provides for an exception: for cases where marking directly on the battery is not possible or not justified due to its type or size. Article 13(7) of Regulation (EU) 2023/1542 states, in essence: Labels must be printed or engraved directly onto the battery — unless the nature or size of the battery makes this impossible or unjustified. In such cases, the label may be affixed to the packaging or included in the accompanying documentation.
This alternative is intended for small batteries, button cells and cylindrical cells below a certain size. In such cases, the physical surface of the battery makes direct labelling technically impractical.
Any decision to place part of the required information on the packaging rather than on the battery itself must be justified by physical constraints relating to the battery’s surface. This includes trademarks and other labelling requirements under EU law. Areas used exclusively for non-essential marketing information are not included.
The argument regarding physical size does not apply to EV battery packs and industrial batteries with a capacity exceeding 2 kWh. These are large components with a substantial surface area. The workaround involving the packaging does not apply. The labelling must be on the battery itself. And it must be indelible.
The economic reality
The EU Battery Regulation applies to all batteries placed on the market in the EU — regardless of where they are manufactured. Regulation (EU) 2023/1542 applies to all new batteries placed on the market or put into service in the European Union from the date of its entry into force. No matter where they come from. No matter where they were produced.
Manufacturers in China, South Korea, Japan and the USA who supply batteries to European customers are subject to exactly the same requirements regarding indelible marking as European manufacturers. The competitive advantage lies with those who have already solved this problem. Those who integrate permanent laser marking into their production process before the deadlines expire. Rather than retrofitting a solution at the last minute when the market surveillance authorities begin their inspections.
The coming months will bring significant changes to the labelling and presentation of batteries. There is still time to prepare — but not much left.
The labelling deadline in August 2026 is fast approaching. The deadline for QR codes and battery passports in February 2027 is not far behind.
A direct answer to a direct question
What does ‘indelible’ mean in the context of the EU Battery Regulation?
This means that the marking is permanently bonded to the battery’s surface. It remains intact throughout the battery’s entire lifespan — including disposal at the end of its life. It can still be read by automated scanning systems even years after manufacture. Furthermore, if the marking can be separated from the battery, it is not indelible.
Adhesive labels are not indelible. Printed labels are not indelible. Surface coatings that can be rubbed off or removed chemically are not indelible.
Laser markings are permanent.
We know exactly what these applications require. If you’re currently looking into how compliance might work in practice for your production process, do get in touch with our engineers. It’s highly likely we’ve encountered a challenge like yours before.
