Supplier data for the battery passport without supplier accounts

Most of what a battery passport says about the inside of a battery does not originate with the battery maker but one step earlier, with the suppliers of its cells and modules. Chemistry, the composition of cathode, anode and electrolyte, hazardous substances, critical raw materials and many cell values therefore have to come from your suppliers. The Battery Regulation backs you up: suppliers of cells and modules provide the necessary information and documentation free of charge (Article 39). The passport, however, remains your responsibility. Two things matter: ask for exactly what is missing, and review every answer before it counts.

This guide covers which data typically comes from suppliers, what the Regulation says about it, why supplier portals with their own accounts struggle in practice, and what a request by link looks like. For the full picture of duties and deadlines, see our battery passport guide.

Which passport data typically comes from suppliers?

Annex XIII of the Battery Regulation sets out what the passport contains. Much of it describes the cell. If you buy cells or modules and build packs or storage systems from them, you often know these details only from a data sheet, and a data sheet is rarely enough for the passport.

Almost all of these belong to the battery model, or more precisely to one technical state of the model. A new cell supplier changes chemistry, composition and cell values: that is a new state, not a correction. Supplier requests therefore belong to a model version, not to individual batteries. This is the materials section of our field registry for stationary storage:

What does the Battery Regulation require of cell and module suppliers?

Article 39 is short. Suppliers of battery cells and battery modules “shall provide the information and documentation necessary to comply with the requirements of this Regulation when supplying battery cells or modules to a manufacturer”, free of charge. Three points matter in practice:

• The scope follows from your obligations. Article 39 contains no list. On its wording it covers whatever you need to meet the Regulation’s requirements, which includes the battery passport.
• Free of charge does not mean free of form. The Regulation sets no format, level of detail or deadline. Put them in the supply contract, together with a duty to report changes to the cell or its materials unprompted.
• The recipient is the manufacturer. Article 39 concerns cells and modules from which you make a battery. An importer of finished batteries from a third country cannot rely on it and needs a contractual arrangement with the manufacturer.

Supply-chain due diligence adds a second rule. From 18 August 2027, economic operators that place batteries on the market must run a battery due diligence policy (Article 48(1) as amended by Regulation (EU) 2025/1561). Companies with a net turnover below EUR 40 million that are not part of a group above that threshold are exempt (Article 47). The duties concern cobalt, natural graphite, lithium, nickel and the compounds based on them that are needed for the active materials (Annex X point 1).

• Your supply-chain documentation must name, among other things, the supplier of the raw material, its country of origin, the transactions up to your immediate supplier and the quantity in the battery (Article 49(2)).
• Your policy belongs in your contracts and agreements with suppliers (Article 49(1)(e)).
• An operator that is itself subject to these duties makes the relevant information available to its immediate downstream purchasers, with due regard for business confidentiality (Article 52(2)).

Whether your cell supplier falls under Article 48 itself depends on whether it places batteries on the market. Do not rely on it; cover the hand-over in the contract. The term is explained in the glossary.

Who is responsible when a supplier gets it wrong?

You are. The economic operator placing the battery on the market ensures that the passport information is accurate, complete and up to date (Article 77(4)). It may authorise others in writing to act on its behalf. The Commission expressly names a cell manufacturer as a possible authorised party, but adds that written authorisation does not transfer the ultimate responsibility (Commission FAQ, question 2.1). In Germany, failing to ensure that passport information is accurate, complete and up to date is an administrative offence with a fine of up to EUR 10,000 (Section 60(2) no. 29 and (3) BattDG).

A supplier value is therefore a claim with a source, not a fact. Before it counts, someone in your organisation checks:

• Does the composition match the chemistry? An LFP cell without iron and phosphate in the cathode is a contradiction.
• Do the quantities add up? The stated masses cannot add up to more than the mass of the battery.
• Is the list complete? A critical raw material that appears in the composition above 0.1 % by weight also belongs in the list of critical raw materials.
• Does the evidence match the value? Same cell type, same figures, current revision of the document.
• Is it detailed enough? For the detailed composition, the Commission considers both the 1 % threshold of the DIN SPEC and the 0.1 % threshold of the draft CEN technical specification potentially reasonable, as long as the result says more than a chemistry label such as “LFP” (Commission FAQ, question 7.7).

Why it matters who entered a value and who reviewed it is the subject of our article on provenance and four-eyes review.

Which supplier data do you need at the start, and which later?

Not everything listed in Annex XIII applies from day one. According to the Commission, carbon footprint, recycled content and due diligence information are not yet required from February 2027, because they have their own application dates (FAQ, question 7.2).

For the later areas you may need to collect supply-chain data to calculate or substantiate results; only the result goes into the passport (FAQ, question 7.3). Ask now for what you need at the start, and announce the rest in the supply contract. All dates are on the timeline; the state of the missing acts is on the implementation status page.

Why do supplier portals with their own accounts struggle?

The obvious answer is a portal where every supplier has an account and maintains its data. In practice several hurdles stand in the way:

• Every customer has its own portal. A cell supplier serves many manufacturers. Each one asks for a registration, a password, terms of use and its own way of working.
• The request is rare. The composition changes only with the cell. An account used once a year is forgotten by the next request.
• Many small suppliers. Besides the cell makers, small firms often supply modules or components. Nobody there maintains yet another customer portal on the side.
• Accounts belong to people. When the person in charge leaves, the account is orphaned and a new invitation is due.
• Internal rules. Some companies do not let their staff register on outside platforms or accept their terms of use without further ado.

What is left is the spreadsheet template by email. It comes back with free text, wrong units and attachments that nobody can match to the right value any more, and who answered what sits in one person’s inbox.

How does a supplier request by link work?

Instead of an account, the supplier gets a link that opens exactly one request. The pattern is simple:

1. You pick exactly the missing fields of a model version.
2. The supplier receives an email with a personal link that is valid until a fixed date.
3. Through the link they see only the requested fields, enter the values and upload evidence for each field.
4. They submit once; after that, the link is used up.
5. The answer arrives in your review as a value with the source “supplier”.

This is how BatteryPass implements the pattern in testing:

• Creating. Members with the editor role or above request model-level fields for one model version, with a recipient, the language of the email (German or English) and an optional message.
• Validity. The link is valid for 14 days by default, up to 60 days if you choose, and for exactly one answer.
• Reminding and cancelling. A reminder, at most once every 24 hours, sends a new link and the old one stops working. If you cancel the request, the link becomes invalid and files already uploaded are deleted.
• Security. The link carries a random token that BatteryPass stores only as a hash. Failed attempts are rate limited.
• Visibility. The supplier sees the name of your company and of the person asking, the model, the version and the requested fields. Other fields of the same section appear only as a status (provided or not), never with their values.
• Evidence. Up to 20 files per request, each assigned to a requested field; they can remove files before submitting.
• Follow-up. Creating the request opens a task for you that closes with the answer, and you get an email. The request, the uploads and the answer are recorded in the audit log.

What happens to the answer before it appears in the passport?

A supplier value is captured, not approved. In BatteryPass it goes through the same steps as any other value:

1. Checks on submission. The form validates format, units and ranges against the field registry. If something is invalid, the supplier sees the message, corrects it and submits again.
2. A new revision with provenance. Each value is stored as a new revision: source “supplier”, a reference to the answer, you as the responsible person, status “captured” or “auto-checked”. Earlier values stay in the history.
3. Evidence on the value. Each file becomes evidence for its field, together with the value the supplier stated and with that field’s access tier.
4. Approval by your organisation. A person with the reviewer, admin or owner role approves the value or rejects it with a reason, which sends a task back to the responsible person.

For the composition and the hazardous substances our field registry requires evidence; without a document the value cannot be approved. If two documents state different values for the same field, an automatic check reports the conflict and the value stays open until one of them is marked as superseded with a reason. Only approved values enter a passport version.

How do you protect your suppliers’ confidential data?

The exact composition of a cell is commercially sensitive. The Regulation takes this into account:

• Public are chemistry, hazardous substances and critical raw materials (Annex XIII point 1(b)).
• Restricted is the detailed composition with the materials of cathode, anode and electrolyte: only persons with a legitimate interest and the Commission may access it (Annex XIII point 2), as well as notified bodies and market surveillance authorities (Article 77(2)).
• Who has a legitimate interest, and what they may download or share, is for an implementing act to decide. One criterion: access to commercially sensitive information is limited to the minimum necessary (Article 77(9)(c)). The deadline passed on 18 August 2026; at our check a draft was open for public feedback, and the act had not been adopted.
• Service providers that store passport data on your behalf may not sell it, or re-use or process it beyond the service (Article 78(d)).

So ask only for what the passport and your documentation really need, state the access tier in the request, and agree confidentiality in the contract. In BatteryPass a supplier’s evidence inherits the access tier of its field, and public pages and exports contain only the public part in testing. Until the implementing act exists, access to the restricted tiers is granted per email address only, and every read is logged limited. More on the access tiers and security pages.

How should you word the request?

Short, specific and with a reason. This sample works as a standalone email. If you send the request from BatteryPass, the email already contains the fields, the link and the deadline; then use only the middle part as your message.

Subject: Battery passport data for [model] with your cell [cell type]

Dear [name],

We are preparing the digital battery passport under Article 77 of Regulation (EU) 2023/1542 for our model [model]. For this we need the following information on [cell type], each with supporting evidence:

1. battery chemistry and the detailed composition of cathode, anode and electrolyte (substance, CAS number, mass), covering every constituent from [1 or 0.1] % by weight;
2. the hazardous substances it contains, with CAS number and concentration;
3. critical raw materials above 0.1 % by weight;
4. the internal resistance of the cell, with test conditions.

Under Article 39 of the Regulation, suppliers of cells and modules provide this information free of charge. The detailed composition does not appear in the public part of the passport; only persons with a legitimate interest and authorities can access it.

Please enter the information through the link by [date]; you do not need an account. If you have any questions, you can reach me on [phone].

Kind regards

[name, role, company]

Where do you start?

1. List the suppliers per model: which cell, which module, from which model version.
2. Find the gaps: which mandatory fields are missing, and who knows the answer.
3. Set the level of detail: threshold for the composition, units, test conditions.
4. Extend the supply contract: cite Article 39, and agree format, deadline, notice of changes, confidentiality and the later data on carbon footprint, recycled content and due diligence.
5. Request per model version: only the missing fields, evidence for each, and a realistic deadline.
6. Review the answers: plausibility, evidence, approval by a second person.
7. Treat a change of cell as a new model version and request the supplier data again.
8. Do not retype answers: a file the supplier sends belongs on the value as evidence.

How supplier answers, imports and your own entries become a reviewed passport is described in From Excel and ERP exports to a reviewed battery passport. Which fields exist and for which category they apply is shown on the data fields page.