EU Battery Passport: Performance and durability data

The EU’s Battery Passport: a focus on performance and durability data requirements

Article 77 of the EU Battery Regulations states all electric vehicles, industrial batteries with capacities of over 2KWh and batteries in light means of transport (LMT, such as e-bikes and e-scooters) will soon need a digital battery passport, or “Battery Passport” (BP) – a paperless data system specifying a diverse set of attributes, from manufacturer information, carbon footprint and electrochemical performance to durability parameters. Helping guide these efforts is the Battery Pass Consortium. TWAICE is involved in the Consortium working on the performance and durability parameters.

But how soon is “soon”?

It’s not a one-shot answer. The hot date for the battery passport is February 2027 – but other performance and durability reporting requirements come into play in August 2024 already. What’s more, the BP covers data both of the battery model and of each individual battery. Accessible through a QR code, it needs to encapsulate numerous data points and must be clearly readable and manage different access levels.

That means any company supplying LMT, EV, or industrial (incl. BESS) batteries to the market needs to understand Battery Passport requirements in detail. This article gives you a head start on doing it.

Why is a battery analytics software developer like TWAICE involved?

Because while the BP represents a step towards a standardized approach for battery data, it isn’t a simple list. Rather, it draws on a number of frameworks from several stakeholders: the above EU Article 77, related Articles including 10, 14, and 17 (along with Annex XIII 4d), and input from working groups including the Battery Pass Consortium itself; the standard will take its final reference form with the EU standardization Mandate 579. These frameworks will set requirements for “economic operators” (legalese for “companies in the market”) placing a battery on the market, i.e. mostly manufacturers or importers to issue BPs from early 2027. The Battery Pass Consortium’s purpose is to act as more of a helpful guide – by showing how a BP will share information securely along the entire battery value chain.

TWAICE and the Battery Pass Consortium

The consortium consists of expert representatives from every field relevant to the Battery Passport – allowing the legal BP requirements to be challenged, clarified, and translated into straightforward guidelines for economic operators. One of the partners advising on performance & durability metrics such as SoH, State of Health – and other metrics that are already part of our Battery Analytics Software – is TWAICE.

So while we’re not consultants or lawyers, we know what information our customers will need to stay compliant– and as part of our thought leadership work in the sector, we’re actively helping to shape developments in a positive way. Which puts us in a position to summarize the current landscape when it comes to the requirements for performance and durability data. Let’s get started!

TWAICE would like to thank acatech’s Johannes Simböck, Circulor’s Niko D'Agostino and Fraunhofer IPK’s Konstantin Neumann of the Battery Pass Consortium for expert advice and context in the preparation of this guide.*

A note on terminology …

First, some terms. EU legislation refers to stakeholders in specific ways, and they may not be wordings you’re familiar with – so let’s list them.

• BESS: Battery Energy Storage System. Stationary batteries that provide electrical storage or backup; usually arrays of many batteries. They can be small scale (for a building) or large (for a town’s power grid).
• Circularity: the principle that materials, components and products should be reusable, recoverable or recyclable to increase energy and resource efficiency– called a “circular economy”. Batteries for EVs and BESS are fast improving on this metric.
• Conformity Assessment: the proof that an economic operator’s Battery Pass contains the right data, collected and used in the right way.  While Conformity Assessment is a well-established tool, there are some challenges regarding digital product passports.
• Data carrier: the generic term used by the EU for any object that provides access to the data system required by the law. For the Battery Passport, that means an optical machine-readable code, which you probably know as a QR code.
• Data format: the structure of information encoded on the battery passport. For the EU, that means adhering to open standards for data storage and presentation, interoperable between applications, and machine-readable. In other words: handwriting the data onto your battery in Magic Marker isn’t an option.
• Economic operator placing the battery on the market: the company responsible for complying with the new regulations – that means anyone manufacturing, supplying or importing batteries covered by the law, including both OEMs, systems integrators, dealers, and distributors.
• Electric vehicle battery: a battery that is specifically designed to provide electric power for traction in hybrid and electric vehicles.
• Light means of transport (LMT) battery: Whereas EV technically covers all electric vehicles powered by battery, in practice the EU separates out smaller mobility choices like e-scooters and e-bikes as LMTs.

… and who the terms apply to

The rules apply to anyone manufacturing or supplying batteries for use in LMTs, EVs, or industrial batteries like BESS, in other words: the economic operator. If you’re reading this, that probably means you. In terms of durability and performance parameters, here are some critical reference documents and how to move forward with them.

At the top level the relevant document is Article 77 of the EU’s battery regulation – but the relevant section, Part A of its Annex IV, doesn’t specify a list of data attributes economic operators will need. Separate but related are the individual requirements for EV and industrial battery suppliers for performance and durability parameters, set out in Articles 10 and 14 of the same law. The good news: you won’t need to become an expert on the minutiae of EU legislation to comply with the new laws. Here are some sources that’ll help.

1. Battery Passport Content Guidance: the data attributes

Your starting point is the 2023 document “Battery Passport Content Guidance”, an easy-to-consume guide to the new requirements published by the Battery Pass Consortium. (Separately available is the “2023 Battery Passport Data Requirements”, a table listing the requirements; it runs to 114 entries.)

As you’d expect from an authoritative source, the guidance is long (a shade under 200 pages) and dense, with 33 figures and 22 tables packed into its 30,000+ words. There is also an easier to read executive summary of the main document. The most useful sections of the guidance are functional rather than legal: the format of the Battery Passport itself with the information this database needs to contain.  

Note this information includes the full scope of required performance and durability data attributes. In addition to unique identifiers for battery and battery passport, there are origin and source data about the manufacturer and compliance symbols for various EU directives and policies. But other proposed data is less straightforward, including circularity, e.g the composition and structure of the battery, sustainability, taking in supply chain information and materials sourcing, and a declaration of the battery’s carbon footprint based on agreed methodology.

So this document contains the current “long list” of data needed – but note not all batteries require the full set.

2. DIN DKE Spec. 99100: a useful companion source

Another useful reference comes from DIN – the “Deutsches Institut für Normung”, which sets standards for many engineered products in Europe’s industrialized giant, Germany. The DIN DKE Spec 99100's goal is to continue the work of the battery pass consortium and to pre-standardize the data attributes mandated for the Battery Passport, including those EU Articles 10 and 14 specifying the performance and durability parameters.

While it’s written from the perspective of the German market, it’s designed to anticipate the EU standard in Mandate 579 – and is somewhat more readable as it focuses on a lean description of data to be reported. While the compliance requirement will be Mandate 579, Spec 99100 is a great piece of guidance – especially as the complete standard may not be finalized until December 2025, and this resource is available soon.

The QR code: how the data carrier works

The “data carrier” – the QR code affixed to each compliant battery – is no different from any other barcode. It isn’t a storage of data itself; rather, it links to a database containing the relevant data, much as those QR codes you scan with your phone link to a web address.

Shared data: the basic performance and durability data set for both EV and BESS batteries

What data does it point to? In addition to source data like unique identifiers and manufacturing locations, here’s the general performance and durability data set each battery’s data carrier must reference to be accepted as a valid Battery Passport. (These apply to both stationary and vehicular batteries.)

• The rated capacity of the battery (in Ah) and capacity fade rate (in %)
• The battery’s output power (in W) and power fade rate (again in %)
• The battery’s internal resistance (in Ω) and internal resistance increase (in %)
• Where applicable, energy round trip efficiency and its fade rate (in %)
• Expected battery lifetime under reference conditions (in cycles and/or years) 

TWAICE’s major role in these discussions is about Battery State of Health (SoH) as part of the Battery Pass Consortium, so watch for updates.

Additional data requirements specific to EV applications

You’ll see the above shared measures are all “static” quantitative ones: numbers that reflect the design of the battery and its expected performance in normal use, the sort of data you could stamp on a spec plate. None of this data is live.

But fulfilment of Article 14 needs more than that, and it’s where BP requirements need to be reflected in your Battery Management System. EV batteries will also need:

• A “declaration” that the BMS contains a SOCE (State of Certified Energy) estimation

In other words: to be compliant with the Battery Passport, the BMS must give an approximation (in %) of the certified battery energy remaining at any point in time. This is obviously important for mobile applications, since the remaining battery energy determines the remaining maximum range of a vehicle and, thus, the remaining lifetime of the battery/vehicle.

Additional requirements for stationery / BESS applications

The list of extra performance/ durability data for BESS is longer – and includes many more confirmations of capability that each battery’s BMS can provide “live” and static data on performance and State of Health. In brief, the Battery Passport must confirm the BMS can indicate:

• The battery’s remaining capacity (units unspecified)
• The remaining power capability (which measures power output in actual use)
• The round trip energy efficiency (which compares energy input with energy retrieved)
• The rate of self discharge (the natural tendency of any battery to discharge over time when not in use)
• The ohmic resistance (in Ω), a sum of all electrical resistances in the battery’s functional parts
• Both date of manufacture and data it entered service (rarely the same; differentiating these indicates how long a battery was stored before deployment)
• Energy throughput in operating conditions
• Capacity throughput in operating conditions
• Any/all harmful events, including number of deep discharges, time in non-optimal temperatures, and time spent charging in extremes of temperature
• The number of FE (full equivalent) charge-discharge cycles

It’s likely the final regulations will specify how often many of these “live” data sources must be updated within the BP. For a discussion of these and other current issues, a useful source is the Position Paper on Content Requirements of the EU Battery Passport, also from the Battery Pass Consortium.

3. Conformity assessment: the role of the BMS and battery analytics

A key part of Article 17 is the “conformity assessment”: how an OEM or supplier proves their Digital Battery Passport answers all the requirements of the law. Essentially, it’s a sense-check that the data referenced in the Battery Passport can be relied on. Vital to compliance are:

• A record of design calculations made (explanations and working of how figures were arrived at)
• Relevant examinations carried out at each phase of manufacturing and putting into service
• Technical and documentary evidence used to reach conclusions (which may include supply chain assurances and due diligence from third parties)
• Proof that methodology for “dynamic” metrics (like product lifetime or aging) was based on acceptable approaches and assumptions

Below you’ll find a few points worth highlighting.

Clarity over point of need

A conformity assessment (CA) needs to happen before a battery enters the market or is put into service (see Article 38). What remains unclear is whether it applies to broad classes of products (such as slight variations between products in the same line) or if each named product will be subject to a separate CA (see Battery Passport Content Guidance).

Batteries are often refurbished and remanufactured. A new CA will be required when such batteries are sold on. The CA always is the responsibility of the manufacturer.

Format of testing and approvals

In addition, note that the actual standard for CA compliance isn’t yet available in full; exemplary testing bodies like TÜV and DEKRA have not yet published their test procedures as a result. There are, however, ongoing efforts to resolve this.

While this lack of clarity is completely normal for emerging areas of regulation, it’s an area economic operators definitely need to watch.

Extent of sanctions for noncompliance

A third area is how broad and deep sanctions are (“remedies” in EU-speak) for companies failing to reach the standards required by the law. So far, Article 84 states that non-compliant companies should either comply with the law (and prove they have done so) or remove their products from the market.

It’s likely that fines and restrictions will be proposed for “rogue” economic operators. This will be in the power of each member state, so fines might differ between countries.

Part of the answer: the role of Battery Analytics Software

TWAICE, of course, supplies Battery Analytics Software, not batteries. And we’re not a legislative consultancy or certification provider. But there’s a big role for Battery Analytics Software to play as these new regulations come into force – and we believe it can make your life a lot easier when it comes to compliance.

After all, Battery Analytics Software plugs into a battery’s BMS to gather data, enriches that data with advanced algorithms and models, then presents that information in context. Giving you valuable information about what’s happening within your battery.

To illustrate, here’s a list of reasons Battery Analytics Software can be more helpful to your compliance efforts than BMS alone:

• TWAICE Battery Analytics uses industry approved standards for data collection and communication – a key part of Battery Passport requirements
• Many performance / durability data attributes are already accessible in TWAICE, allowing (for example) Conformity Assessments to be completed faster and easier
• The software can collect data at short or long intervals, meaning that when intervals are specified in EU law, Battery Analytics Software is capable of providing answers
• The software can provide a range of other metrics around temperature and operating conditions, providing a solid basis for claims about product expected lifetime and performance characteristics in different locales.
• TWAICE software goes beyond the BMS, actively analyzing data rather than simply collecting and displaying – letting you explore a range of scenarios when developing different battery products subject to compliance

In short, TWAICE Battery Analytics Software makes data from your battery’s BMS visible, demonstrable, and easy to understand. Which is a huge help in making your products viable and successful in your markets as the BP requirements come into force.

The BP is a moving target – but TWAICE can help

As one of the Battery Pass Consortium members, TWAICE has been involved in the new EU regulations since the beginning: learning them, explaining them, and (in some cases) influencing them. We’re determined to continue this work and provide software that makes it as easy and straightforward as possible for you to comply with the Battery Passport regulations as your business goes forward.

While we can’t advise on legal outcomes, foresee the final state of legislation, or consult on battery passport compliance, one thing is clear: transparency into your batteries is key. Because the better you understand your batteries and the more deeply you can analyze your data, the easier a Conformity Assessment will be.

We hope you found this summary of the upcoming regulatory landscape useful – and if you’d like to see what TWAICE Battery Analytics can bring to your company, contact us here!

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* Any errors or omissions in this document are the responsibility of TWAICE not our interviewees. TWAICE does not take responsibility for any consequences resulting directly or indirectly from the use of information contained in this document.

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