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Our Cell Supplier Won't Share Data — Can We Still Publish a Battery Passport?
What to do when the cell manufacturer ignores your passport data requests: what you can demand, how verifiable evidence works without exposing supplier secrets, and when to switch suppliers.
The short answer
You can't publish a truthful passport around a data hole — but the data you actually need from a cell supplier is narrower than most assemblers assume, and there are established mechanisms for suppliers to prove claims without opening their books. The right move is to make your request specific, contractual, and evidence-based — and to treat a supplier who still won't engage as a supply-chain risk, not a paperwork annoyance.
What you actually need from them
Not their process know-how. The passport-relevant supplier dataset is:
- Cell chemistry and critical raw material content — cobalt, lithium, nickel, natural graphite by weight share.
- Origin data — manufacturing facility and the origin countries feeding their material inputs.
- Due-diligence report references — for the four critical raw materials, aligned with OECD guidance.
- Carbon footprint contribution — calculated per the regulation's methodology, not a marketing PCF.
- Performance data — rated capacity and cycle-life documentation for your durability fields.
How suppliers prove claims without exposing secrets
The emerging technical pattern (used in W3C Verifiable Credential–based battery passports) separates the claim from the evidence: the passport carries a declared value plus a link to an external certificate, with a cryptographic hash so anyone can confirm the document hasn't been altered. The supplier's certifier hosts the evidence; you reference it. Nobody's proprietary process data changes hands.
This matters in negotiations: a supplier objecting that "our data is confidential" is usually objecting to a request you don't need to make. Reframe the ask as declared values plus verifiable certificate references, and the confidentiality objection mostly evaporates.
The escalation ladder
- Specific request — a field list, not "please send compliance data." Vague requests get vague PDFs.
- Contractual delivery — passport data as a deliverable in the supply agreement, with the field list as an annex. New POs are your leverage moments.
- Procurement pressure — passport-readiness is now a qualification criterion in serious RFPs. Suppliers hear "no data, no orders" faster than they hear compliance arguments.
- Supplier substitution — a cell maker that cannot produce chemistry, origin, and due-diligence documentation in 2026 is telling you something about what else they can't produce. Some EU cell manufacturers now market passport-readiness explicitly as a differentiator; the market is giving you alternatives.
The uncomfortable case: data that doesn't exist
If your supplier can't provide provenance because the cells are grey-market, salvaged, or of unknowable origin, the passport hasn't created a new problem — it's exposed an old one. No publishing tool can fix that; a passport wrapped around fabricated provenance is fraud with better formatting. That's a sourcing decision, and 2026 is the year to make it.
What this means for your team
Send the specific field list to every cell supplier this month, attach it to the next PO as a contractual annex, and log who responds. The responses — and the silences — will tell you more about your 2027 readiness than any internal audit.