A Digital Battery Passport is only as reliable as the information behind it. Battery manufacturers depend on suppliers for details about raw materials, components, manufacturing processes and product performance. If these records are incomplete, inconsistent or difficult to verify, building an accurate Battery Passport becomes significantly more challenging.
As discussed in our previous article, APIs and data spaces for Battery Passport data exchange, information must move between organisations and systems in a structured and controlled way. However, before deciding how to exchange it, manufacturers need to establish what information they should request from suppliers.
For procurement, supply-chain and compliance teams, this means developing clear supplier data requirements, defining acceptable evidence and establishing processes for keeping information up to date.
1. Start With Product and Component Identification
The first step is knowing exactly what a supplier provides and where it fits within the battery.
Manufacturers should request consistent identification information for each relevant material, component or sub-assembly. Depending on the product, this may include:
- Supplier's legal name and manufacturing site.
- Component or material name, description and part number.
- Product specification, grade and chemistry.
- Batch, lot or serial number, where applicable.
- Country of origin and manufacturing location.
- Applicable technical specifications and declarations.
These details help manufacturers connect supplier records to their own bills of materials (BOMs), production records and battery models. They also support traceability when a component or material changes, or when a quality issue needs to be investigated.
A useful practice is to request information at the level at which it can be reliably traced. For example, a material specification may apply to a product model, while a certificate or test result may relate to a particular production batch.
2. Request Material Composition and Technical Data
Battery manufacturers need accurate information about the materials and components used in their products. This is particularly important for identifying critical raw materials, understanding battery chemistry and supporting downstream activities such as repair, dismantling and recycling.
Depending on the supplier's role, manufacturers should request:
- Chemical composition and relevant material declarations.
- Information on critical raw materials, including lithium, cobalt, nickel and natural graphite where applicable.
- Details of hazardous substances and relevant safety information.
- Technical specifications and performance characteristics.
- Relevant test reports, certificates and quality documentation.
- Component drawings, part references and replacement information where relevant.
The level of detail should reflect the component and its role in the battery. A cell supplier, for example, may need to provide chemistry, capacity and performance information, while a casing supplier may provide material specifications and relevant substance declarations.
Manufacturers should also distinguish between information required for the Battery Passport and additional technical information needed for their own engineering, quality and safety processes.
3. Collect Sustainability and Responsible Sourcing Information
Supplier data is also important for understanding the environmental and social impacts associated with battery production.
Manufacturers should establish what sustainability information suppliers can provide and what supporting evidence is available. Depending on the material, process and applicable legal requirements, requests may cover:
Carbon footprint and environmental data: Ask for relevant emissions data, energy consumption, production processes and supporting information used in product or material carbon footprint calculations. Clarify the reporting period, system boundaries, methodology and whether figures are based on primary or secondary data.
Recycled content: Request the proportion of recycled material, the material concerned, the calculation method and supporting documentation. Where relevant, distinguish pre-consumer and post-consumer recycled content.
Responsible sourcing: Request information on the origin of relevant raw materials, supply-chain due diligence processes, risk assessments and measures taken to address identified environmental or human rights risks.
Certifications and declarations: Collect applicable environmental management certificates, material declarations, audit records and supplier sustainability reports. Check their validity, scope and issuing organisation rather than treating a certificate as proof of every sustainability claim.
Not every supplier will hold all this information directly. Manufacturers may need to establish reporting arrangements with upstream suppliers, particularly where raw materials pass through several processing and trading stages.
4. Ask For Evidence, Not Just Data
A supplier questionnaire can collect useful information, but a completed form does not automatically make the information reliable. Manufacturers should ask suppliers to provide evidence that supports important declarations and figures.
Depending on the data point, suitable evidence may include laboratory test reports, material certificates, bills of materials, product specifications, audit records, declarations of conformity and traceability documentation.
Each submission should ideally identify:
- The source of the information.
- The organisation or person responsible for providing it.
- The date of issue and applicable reporting period.
- The product, component, site or batch covered.
- The methodology or standard used, where relevant.
- Any limitations, assumptions or exclusions.
Manufacturers should also establish a process for checking documents, resolving inconsistencies and recording approval decisions. This creates a stronger basis for demonstrating where information originated and how it was assessed.
For further guidance, see battery data provenance and evidence of data origins.
5. Define Data Formats, Updates and Responsibilities
Supplier information often arrives in different formats, from spreadsheets and PDF certificates to structured system exports. Without common requirements, procurement teams may spend considerable time reconciling records and correcting inconsistencies.
Manufacturers should provide suppliers with standard data templates, agreed units of measurement, accepted file formats and clear definitions for requested fields. Where possible, these requirements should align with relevant Battery Passport data models and standards.
They should also agree on when information must be submitted and updated. For example, a supplier should notify the manufacturer when a material specification, manufacturing site, production process or declared composition changes.
A supplier data agreement can define submission deadlines, update frequency, notification procedures, evidence retention and responsibility for correcting inaccurate information.
This is particularly important when a battery model or component remains in production for several years. Manufacturers need a way to distinguish current information from older records and preserve the history of changes. Mapping existing business data to Battery Passport requirements and managing Battery Passport data changes over time provide useful guidance on these processes.
6. Build A Practical Supplier Data Request Process
A structured process can make supplier engagement more manageable. Rather than sending every supplier an extensive questionnaire, manufacturers can tailor requests to the materials, components and information each supplier is responsible for providing.
A practical approach involves four steps:
- Map the supply chain: Identify relevant suppliers, components, materials and manufacturing sites.
- Define data requirements: Match each supplier category to the information and supporting evidence required.
- Assess data quality: Check completeness, consistency, validity and traceability before accepting submissions.
- Maintain and review records: Establish update schedules, track missing information and follow up on changes.
A supplier data register can help procurement and compliance teams monitor progress. It might record the supplier, component, requested data points, evidence received, validation status, outstanding issues and last update date.
Over time, this register can become an important input to the organisation's wider Battery Passport data management process.
What Does This Mean for Battery Passport Compliance?
Under the EU Batteries Regulation (EU) 2023/1542, the Battery Passport becomes mandatory from 18 February 2027 for electric vehicle batteries, light means of transport batteries and industrial batteries with a capacity greater than 2 kWh placed on the EU market or put into service.
The obligation to create and maintain the passport rests with the economic operator placing the finished battery on the market, not automatically with every supplier of its individual materials or components. Nevertheless, manufacturers need relevant supplier information to substantiate applicable declarations and populate the required passport fields.
It is also important to recognise that not every data requirement applies from February 2027. The European Commission's guidance distinguishes between mandatory, optional and conditionally applicable information, while certain carbon footprint, recycled content and due diligence requirements have separate application dates. Suppliers and manufacturers should therefore align their data requests with the applicable requirements and implementation timeline.
How BASE Supports Better Battery Data Management
The BASE project, Battery Passport for Resilient Supply Chain and Implementation of Circular Economy, is working towards a trusted and interoperable Digital Battery Passport framework. Reliable supplier information is an important foundation for this work because battery data originates across multiple organisations and stages of the value chain.
By addressing data traceability, validation, interoperability and secure information exchange, BASE contributes to approaches that can help organisations manage battery information more consistently. A structured supplier data process supports this wider objective by making information easier to assess, connect and use throughout the battery lifecycle.
Closing Thoughts
Preparing for Battery Passport implementation starts well before passport publication. Manufacturers need to understand what information their suppliers hold, what evidence supports it and how it can be maintained over time.
Clear data requests, consistent formats, evidence-based validation and agreed update responsibilities can help procurement and supply-chain teams build a more reliable information foundation. With these processes in place, supplier data becomes easier to manage and more useful for Battery Passport implementation, compliance and lifecycle traceability.
The BASE project has received funding from the Horizon Europe Framework Programme (HORIZON) Research and Innovation Actions under grant agreement No. 101157200.
References & Resources
European Union - Regulation (EU) 2023/1542 Concerning Batteries and Waste Batteries: https://eur-lex.europa.eu/eli/reg/2023/1542/oj
European Commission - EU Digital Product Passport FAQ for Batteries: https://single-market-economy.ec.europa.eu/single-market/digital-product-passport/eu-digital-product-passport-faq-batteries_en
European Commission - Guidance to support preparations for the Digital Batteries Passport: https://single-market-economy.ec.europa.eu/news/guidance-support-preparations-digital-batteries-passport-2026-08-21_en
European Commission - Digital Product Passport for Batteries (Battery Passport): https://single-market-economy.ec.europa.eu/single-market/digital-product-passport/batteries_en