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EVstring
EU 2027Battery passports become mandatory on 18 Feb 2027

Every product, a verifiable story.

EVstring is a digital product passport platform, built first for EV batteries. Each product gets one lifelong record, shared by every company that handles it and anchored on a permissioned blockchain, so no single party can rewrite its history. Chargers, solar panels, electronics and textiles run on the same engine.

Book a demo Try the public passport
  • Annex XIII data model
  • No personal data on-chain
  • Contract-enforced lifecycle
A battery's lifecycle, anchored block by blockA battery passport moves through seven states, from manufactured to recycled. Each state change is written as a new block linked to the previous one, forming a tamper-evident history.PassportEVS-ACME-2026-000001MANUFACTUREDManufacturedInstalledIn useServiceRetiredSecond lifeRecycledpermissioned chain · AssetLifecycle#48109f3a1cBlock 4810: Manufactured#48174be07dBlock 4817: Installed#4824c21f88Block 4824: In use#483107d4aeBlock 4831: Service#4838e5a930Block 4838: Retired#48453c6b12Block 4845: Second life#4852a8f04eBlock 4852: RecycledLifecycleEvent → MANUFACTURED · Manufacturer · 0x9f3a1c…

Regulation (EU) 2023/1542

From 18 February 2027, every EV, LMT and industrial battery above 2 kWh placed on the EU market needs a digital battery passport.

The passport must be reachable through a QR code on the battery, carry information on composition, carbon footprint, recycled content, performance and durability, and expose different detail to the public, to parties with a legitimate interest, and to authorities. India, the United States and China are each building their own traceability and extended-producer-responsibility rules.

Global regulations explained How EVstring maps to each requirement

Why it matters

Battery data is scattered, editable and lost at the first change of hands.

A battery outlives the vehicle it ships in, changes owners several times and ends up with a recycler who has never seen its records. Today every hand-off loses information and trust.

Opaque supply chains

Today: Composition, origin and carbon data sit in PDFs and separate ERPs.

With EVstring: One shared, verifiable passport per battery.

History nobody can trust

Today: Service and health records get lost or edited, so second-life buyers discount every claim.

With EVstring: An append-only lifecycle log, with telemetry anchored on-chain.

Regulatory deadlines

Today: Battery passports become mandatory in the EU in February 2027; other markets are following.

With EVstring: A data model built on Annex XIII of Regulation (EU) 2023/1542.

End-of-life leakage

Today: Batteries disappear from view after the first owner, and recycling rates suffer.

With EVstring: Custody and state follow the battery all the way to the recycler.

Unprovable recycling

Today: Recovered material quantities are hard to prove to customers and authorities.

With EVstring: Recyclers record recovered lithium, cobalt, nickel and more on-chain.

One passport. Seven roles. A history no single party can rewrite.

Explore the platform

The platform

Everything a battery passport needs, in one place.

From the first registration to the final recycling certificate, EVstring keeps the data where it belongs and the proof where nobody can change it.

All capabilities

Register & identify

Each battery gets a passport ID, a QR code and an ERC-721 passport token. Specs stay off-chain; their SHA-256 fingerprint goes on-chain.

Lifecycle & custody

Seven states from manufactured to recycled. Smart contracts decide which role may make which transition, and custody transfers are signed.

Tamper-evident documents

Certificates and reports are hashed and anchored. Anyone holding a copy can check it against the chain in seconds.

Public passport

A fast, mobile-first page behind every QR code, showing only public-tier data: no VINs, no owner details.

Material recovery

Recyclers record the materials recovered from each product, from lithium and cobalt to glass and silver, against the passport it came from.

Regulator analytics

Auditors see complete event trails and market-wide views by lifecycle phase, product type and recovered material.

How it works

Data stays private. Proof becomes public.

EVstring never puts your specifications or documents on a blockchain. It stores a cryptographic fingerprint of them, which proves the data has not changed without revealing what it says.

  • Permissioned EVM network: known validators, fast finality, no cryptocurrency.
  • Six focused smart contracts enforce roles and lifecycle rules.
  • Restricted documents are encrypted before they are stored.
See how it works

  1. Step 1

    Record stays off-chain

    Specs, certificates and readings live in an access-controlled database or encrypted IPFS storage.

    { "passportId": "EVS-ACME-…",
  "chemistry": "NMC 811",
  "capacityKWh": 75 }

  2. Step 2

    Fingerprint with SHA-256

    A 256-bit hash is computed. Change one byte of the record and the fingerprint changes completely.

    bdfd7596 8757e492 23efdea7 06537acc…

  3. Step 3

    Anchor it in a block

    Only the fingerprint is written to the permissioned chain, signed by the acting organisation.

    block #4,817 · DocumentRegistry
    signer 0x7a1…e04 (Manufacturer)

  4. Step 4

    Anyone can verify

    Re-hash the record you were given, compare it with the chain, and get a clear verified or tampered answer.

    VERIFIED · hashes match

Solutions

Built for every company that touches the battery.

Each organisation joins with one role. The platform shows it exactly the actions and data that role is entitled to.

Manufacturers

Register batteries, publish composition and carbon data, and meet passport obligations.

Vehicle OEMs

Link packs to vehicles without exposing VINs, and keep traceability through after-sales.

Fleets

Prove battery health and history to lessors, insurers and the next buyer.

Service centres

Log diagnostics and repairs against the right battery, in a record that cannot be quietly changed.

Second-life operators

Buy retired packs with a history you can actually verify before you pay.

Recyclers

Take custody, close the passport, and evidence the materials you recover.

Regulators & auditors

Read-only access to complete audit trails and market-wide analytics.

Your role?

Integrators, insurers, lessors and logistics partners can be onboarded too. Tell us about your use case.

Security & trust

Defence in depth, from the API to the contract.

Every state change is checked twice: once by the API's role guard and once by the smart contract itself. Even a compromised application server cannot push a battery into a state its role is not allowed to set.

Hash-only ledger

Personal data never goes on-chain. VINs are stored as salted hashes.

Encrypted documents

AES-256-GCM with a per-document key before anything reaches IPFS.

Tiered access

Public, restricted and regulator tiers modelled on Annex XIII.

Full audit trail

Every transition carries the acting organisation, a timestamp and a transaction hash.

Visit the trust centre

Beyond batteries

Available

One trust layer for every regulated product.

The EU's Ecodesign for Sustainable Products Regulation extends the digital product passport idea well beyond batteries. In EVstring each product type is a versioned definition (fields, lifecycle, who may do what, documents, recovery records) that the smart contracts enforce. The prototype ships five templates; more types are added as data, not code.

  • EV batteries
  • EV chargers
  • Solar panels
  • Consumer electronics
  • Textiles & apparel

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See a battery passport end to end.

We will walk you through registration, lifecycle events, the public QR passport and tamper-evident verification, using your own battery categories as the example.

Book a demo Try the public passport