One EV battery. Seven checkpoints. Three countries. Eighteen months. Cryptographic phase gates prove every stage was complete before the next began.
Who this is for: Battery OEM compliance leads, Notified Body assessors evaluating DPP readiness, recyclers and second-life operators verifying chain of custody, automotive Tier 1 suppliers preparing for EU Battery Regulation obligations, insurance underwriters pricing battery warranty risk, and carbon auditors verifying lifecycle emissions claims.
EuroBatt GmbH manufactures EV battery packs for a European automaker. A single battery pack travels through three countries over eighteen months before reaching the end customer:
| Stage | Location | Duration | Activity |
|---|---|---|---|
| Cell production | Erfurt, Germany | Months 1-3 | NMC cell manufacturing, formation cycling, quality grading |
| Module assembly | Wroclaw, Poland | Months 4-6 | Cell-to-module integration, thermal management, BMS calibration |
| Pack integration | Lyon, France | Months 7-9 | Module-to-pack assembly, pack-level testing, vehicle integration |
| Vehicle integration | Lyon, France | Months 9-10 | Pack installed in vehicle, system-level validation |
| Field operation | End customer (EU-wide) | Months 10-18+ | Charging cycles, degradation monitoring, warranty period |
| Second life | Varies | Post-vehicle | Stationary storage repurposing, SoH assessment |
| Recycling | Antwerp, Belgium | End of life | Material recovery, recycling efficiency documentation |
The EU Battery Regulation (Regulation 2023/1542) requires a Digital Product Passport for every EV battery placed on the EU market from February 18, 2027 (with a transition period allowing batteries manufactured before that date to be placed on the market until August 18, 2027). The DPP must be accessible throughout the battery's lifetime and updated at each lifecycle stage. Three implementing acts define the technical details: Commission Delegated Regulation 2024/1690 (DPP data carrier specifications), 2024/1701 (carbon footprint calculation methodology), and 2024/1689 (battery unique identifier registry, IDNR). The question is: how do you prove that each stage actually happened, in the right order, with the right data, across three countries and multiple operators?
This guide shows how SWT3 hierarchical Merkle trees create an end-to-end cryptographic evidence chain for that entire lifecycle. The DPP becomes more than a data repository. It becomes a tamper-evident proof of process integrity.
Five articles create the compliance surface that this scenario addresses:
Every industrial and EV battery must carry a DPP with a unique identifier, accessible via a data carrier (QR code). The DPP must include: manufacturer identity, manufacturing date and place, battery chemistry, capacity, carbon footprint declaration, supply chain due diligence information, and end-of-life collection and recycling information. The passport must be updatable throughout the battery's lifecycle.
Manufacturers must declare the carbon footprint of each battery model, covering raw material extraction, manufacturing, transportation, and end-of-life processing. The declaration must follow the methodology in the delegated acts and be independently verified. Maximum carbon footprint thresholds will apply from 2028.
Economic operators must implement due diligence policies for raw materials (cobalt, lithium, nickel, natural graphite). This includes risk identification, third-party audits, and grievance mechanisms. Due diligence must be documented and reported.
Before a battery is repurposed for second-life applications, its state of health must be assessed and documented. The original manufacturer's DPP data must be accessible to the second-life operator. The repurposing operator becomes the new economic operator and inherits reporting obligations.
Market surveillance authorities may check the accuracy of DPP data, verify that the data carrier (QR code) functions correctly, and demand proof that DPP information matches actual battery properties. Authorities can request documentation proving that each lifecycle stage was completed as declared. Non-compliant batteries may be withdrawn from the market or recalled.
Assessor Note
The DPP is not a one-time filing. It is a living document that must be updated at each lifecycle stage. When evaluating DPP compliance, verify that the passport contains evidence from all completed lifecycle stages, not just manufacturing. A DPP with only factory data and no field operation or end-of-life records is incomplete. Article 76 gives market surveillance authorities the power to demand this evidence at any time.
Each checkpoint represents a lifecycle stage where evidence must be recorded. The SWT3 procedures that apply at each checkpoint are listed below.
Formation cycling results, capacity grading, impedance measurements, cell-level defect screening. Raw material sourcing documentation (Art. 11 due diligence).
Procedures: HBOM-INV.1 (cell inventory), HBOM-SUPPLY.1 (supply chain provenance), DPP-CHRG.1 (formation charge/discharge cycles)
Cell-to-module integration, welding quality, thermal interface verification, BMS initial calibration. Module-level capacity and resistance testing.
Procedures: HBOM-THERM.1 (thermal profile attestation), HBOM-LIFE.1 (component lifecycle witnessing), DPP-SOH.1 (initial state of health baseline)
Module-to-pack assembly, pack-level high-voltage testing, cooling system verification, crash structure integration, final BMS programming. Pack-level SoH certification.
Procedures: DPP-SOH.1 (pack-level SoH), HBOM-THERM.1 (pack thermal validation), HBOM-INV.1 (pack-level hardware inventory)
Pack installed in chassis, system-level HV interlock test, charge/discharge validation at vehicle level, CAN bus communication verification. Vehicle-level SoH baseline established.
Procedures: DPP-SOH.1 (vehicle-integrated SoH), DPP-CHRG.1 (vehicle-level charge cycle validation)
Ongoing charge/discharge cycle witnessing, degradation event recording, thermal excursion logging. The BMS or connected vehicle platform periodically reports SoH data. This is the longest phase and produces the most evidence.
Procedures: DPP-CHRG.1 (ongoing cycles), DPP-DEGRAD.1 (degradation events), DPP-SOH.1 (periodic SoH snapshots), HBOM-THERM.1 (thermal excursions)
Battery removed from vehicle. Independent SoH assessment determines if the pack qualifies for second-life stationary storage (Art. 14). The repurposing operator inherits the DPP and must continue updating it.
Procedures: DPP-SOH.1 (second-life SoH assessment), DPP-DEGRAD.1 (cumulative degradation summary), HBOM-LIFE.1 (lifecycle stage transition)
End-of-life disposition. The recycler receives the battery with its full DPP history, documents the recycling process, and records material recovery rates. The DPP is finalized but must remain accessible for regulatory audit.
Procedures: DPP-EOL.1 (end-of-life/recycling handoff), HBOM-SUPPLY.1 (recovered material provenance)
Assessor Note
When evaluating a battery DPP, check that all seven checkpoints have evidence. A common gap: Checkpoint 5 (field operation) often has sparse data because the OEM relies on the vehicle platform to report, and connected services may have gaps. Ask for the DPP-CHRG.1 anchor count during the field operation phase. A typical EV charged every 2-3 days generates 120-180 charge events per year. If the vehicle was in service for 12 months but has fewer than 100 DPP-CHRG.1 anchors, investigate the reporting pipeline. For fleet vehicles with daily charging, expect 300+ anchors per year. For infrequent-use vehicles (weekend cars, seasonal), adjust the threshold downward but document the justification.
The seven checkpoints map to a three-tier hierarchical Merkle tree. Each checkpoint is a milestone. Related checkpoints group into phases. All phases roll up to a single structure root representing the complete battery lifecycle.
Individual attestation fingerprints (inspections, tests, sensor readings)
+----------+ +----------+ +----------+ +----------+
| HBOM-INV | | HBOM-SUP | | DPP-CHRG | | DPP-SOH |
+----+-----+ +----+-----+ +----+-----+ +----+-----+
| | | |
+------+-----+ +-----+------+
v v
+--------------+ +--------------+
| MS: Cell QC | | MS: Module | Milestone roots
| (Checkpoint 1)| | (Checkpoint 2)|
+------+-------+ +------+-------+
| |
+--------+ +---------+
v v
+--------------+
| Phase: | Phase root
| Manufacturing|
+------+-------+
|
+--------------+----------------+--------+
v v v v
Manufacturing Integration Operation End-of-Life
Phase Phase Phase Phase
(CP 1-2) (CP 3-4) (CP 5) (CP 6-7)
| | | |
+--------------+----------------+--------+
|
+--------------------+
| Structure Root | Single hash
| "Battery Pack |
| EBG-2026-0417" |
+--------------------+Four-phase structure: Manufacturing (cells + modules), Integration (pack + vehicle), Operation (field), End-of-Life (second life + recycling). Each checkpoint is a milestone within its phase.
| Phase | Checkpoints | Countries | Duration |
|---|---|---|---|
| Manufacturing | 1 (Cell QC), 2 (Module Assembly) | Germany, Poland | Months 1-6 |
| Integration | 3 (Pack), 4 (Vehicle) | France | Months 7-10 |
| Operation | 5 (Field) | EU-wide | Months 10-18+ |
| End-of-Life | 6 (Second Life), 7 (Recycling) | Varies, Belgium | Post-vehicle |
The structure root is a single hash that represents the complete cryptographic state of this battery's lifecycle. Change one attestation at any checkpoint and the structure root changes. The math is the audit trail.
A phase gate between Manufacturing and Integration ensures that cell QC and module assembly are complete before the pack assembly line receives the modules. The gate is not a management decision. It is a cryptographic check: every required procedure in the Manufacturing phase must have a terminal PASS verdict. If any cell failed QC and was not remediated, the gate blocks. The modules cannot advance to Lyon until the math says they can.
Assessor Note
Verify the GATE_OPEN timestamp for the Manufacturing-to-Integration transition. It must precede the first attestation in the Integration phase. If pack integration attestations exist before the manufacturing gate opened, either the gate was overridden (check for an override leaf) or the evidence was backdated (compare ledger timestamps). Both are findings.
The battery crosses three EU member state borders. Each country has its own market surveillance authority, its own conformity assessment expectations, and potentially different interpretations of the delegated acts. The DPP must be consistent regardless of where the evidence was generated.
| Country | Authority | Checkpoints | Key Requirements |
|---|---|---|---|
| Germany | Decentralized: state-level market surveillance authorities (Landesgewerbeamter) coordinated through ZLS. Battery registration via UBA (Umweltbundesamt). | 1 | Cell-level QC, raw material due diligence (Art. 11), carbon footprint declaration origin data |
| Poland | Trade Inspection Authority (Inspekcja Handlowa) for product compliance; Chief Inspectorate of Environmental Protection (GIOS) for environmental/recycling aspects. | 2 | Module assembly quality, thermal management validation, component traceability |
| France | DGCCRF (Direction Generale de la Concurrence, de la Consommation et de la Repression des Fraudes) for product compliance; ADEME for sustainability reporting. | 3, 4 | Pack-level conformity, vehicle integration, Art. 77 DPP data carrier placement |
Note: Market surveillance under the EU Battery Regulation is decentralized per Article 76. Each member state designates its own competent authorities. The authorities listed above are illustrative; operators should verify current designations with their national implementation of the regulation.
SWT3 witness anchors carry jurisdiction metadata. Each attestation records the jurisdiction where the evidence was generated. When a German market surveillance authority inspects the DPP, it can filter for all attestations generated in Germany and verify them independently, without needing access to the Polish or French evidence systems.
The Carbon Border Adjustment Mechanism (CBAM) applies to imported batteries from third countries. For batteries manufactured entirely within the EU (like this scenario), CBAM does not apply directly. However, the carbon footprint declaration required by Article 7 uses the same evidence chain. If EuroBatt sources cathode materials from a non-EU supplier, the HBOM-SUPPLY.1 attestation for that material includes the embedded carbon data that feeds into the CBAM-adjacent reporting.
Assessor Note
Cross-jurisdictional verification: request the structure root and then request multi-tier proofs for one attestation from each country (Germany, Poland, France). All three proofs must resolve to the same structure root. If they do not, the evidence chain has been tampered with or the structure was rebuilt without including all jurisdictions.
Article 11 requires supply chain due diligence for cobalt, lithium, nickel, and natural graphite. The due diligence audit happens once at source (Checkpoint 1 in Germany), but the evidence must be traceable through every subsequent phase. EuroBatt does not re-audit the cobalt supplier at each factory -- instead, the original HBOM-SUPPLY.1 attestation from Checkpoint 1 is referenced by downstream milestones via the multi-tier proof.
When the module assembly team in Wroclaw receives cells from Erfurt, they reference the Cell QC milestone root (which contains the HBOM-SUPPLY.1 attestation) in their HBOM-INV.1 inventory attestation. The Pack Integration team in Lyon does the same. At any point, an auditor can trace the material provenance from the pack back to the original due diligence attestation in a single proof chain -- without the downstream operators needing to store or duplicate the original evidence.
Assessor Note
Due diligence inheritance is verified by requesting a multi-tier proof for the HBOM-SUPPLY.1 attestation from Checkpoint 1 and confirming it resolves to the current structure root. If the structure root has changed since the due diligence was performed (because new phases were added), the proof still resolves because the Manufacturing phase root is immutable once the phase gate closes. The due diligence evidence is cryptographically locked into the tree at the time of attestation.
Month 14. The battery has been in field operation for four months. The vehicle's BMS detects an anomaly: capacity has dropped 3.2% in two weeks, which exceeds the normal degradation rate. This is a DPP-DEGRAD.1 event.
The connected vehicle platform sends a degradation attestation to the SWT3 witness endpoint. The attestation includes the degradation cause code, the SoH delta, and the ambient temperature at the time of detection.
# Connected vehicle platform reports degradation
from swt3_ai import Witness
witness = Witness(
endpoint="https://sovereign.tenova.io/api/v1/witness",
api_key="axm_live_...",
tenant_id="eurobatt-gmbh",
agent_id="bms-telemetry-agent",
flush_interval=300
)
# DPP-DEGRAD.1: degradation cause 2 (accelerated capacity fade),
# SoH delta 3.2%, ambient temp 38C
witness.witness_inference(
model_id="bms-degradation-v2",
procedure="DPP-DEGRAD.1",
input_data={"vin": "WBA...7890", "pack_id": "EBG-2026-0417"},
output_data={"cause_code": 2, "soh_delta_pct": 3.2, "ambient_c": 38},
factor_a=2, # degradation cause: accelerated capacity fade
factor_b=32, # SoH delta x10 (3.2%)
factor_c=38, # ambient temperature Celsius
milestone_id="MS-field-ops",
phase_id="PH-operation",
structure_id="ST-ebg-2026-0417"
)The attestation becomes a leaf in the Field Operation milestone. The milestone root recomputes. The Operation phase root recomputes. The structure root recomputes. The DPP now reflects the degradation event.
The OEM investigates. The root cause is thermal stress from repeated fast charging in high ambient temperatures (38C+ days in southern France). The BMS thermal management was within spec, but the usage pattern exceeded the thermal design envelope.
The warranty team queries the DPP evidence chain. They pull all DPP-CHRG.1 attestations for this battery during the field operation phase and all HBOM-THERM.1 thermal excursion records. The evidence shows 47 fast charge events above 35C ambient in the last 60 days. The battery's thermal profile attestations confirm the cooling system operated within spec -- the degradation was caused by customer usage patterns, not a manufacturing defect.
For Insurers and Warranty Providers
The degradation event, the root cause investigation, and the warranty determination are all in the same Merkle tree. The insurer can verify: (1) the degradation event timestamp and magnitude, (2) the charging pattern that caused it, (3) that the thermal management system was operating correctly at the time. All three are independently verifiable with multi-tier proofs that resolve to the same structure root. No filing cabinets. No email chains. One hash.
The degradation event and the warranty determination are now part of the battery's permanent record. When this battery reaches Checkpoint 6 (second life assessment), the repurposing operator will see the full degradation history, including the root cause. The SoH assessment for second-life qualification will account for the thermal stress pattern.
Assessor Note
When evaluating a DPP with degradation events, check the temporal sequence: DPP-DEGRAD.1 attestation timestamp, followed by investigation evidence (if recorded), followed by any warranty determination. Verify that the degradation cause code is consistent with the supporting thermal and charging data. A cause code of "manufacturing defect" with thermal data showing customer abuse is a red flag.
from swt3_ai.milestone_merkle import MilestoneAccumulator, verify_multi_tier_proof
# Create the battery lifecycle structure
acc = MilestoneAccumulator(structure_id="ST-ebg-2026-0417")
# Phase 1: Manufacturing (Germany + Poland)
acc.add_phase("PH-manufacturing", "Manufacturing", sequence=0,
required_framework="EU-BATTERY-REG")
# Phase 2: Integration (France)
acc.add_phase("PH-integration", "Integration", sequence=1,
required_framework="EU-BATTERY-REG")
# Phase 3: Operation (field)
acc.add_phase("PH-operation", "Operation", sequence=2,
required_framework="EU-BATTERY-REG")
# Phase 4: End-of-Life
acc.add_phase("PH-eol", "End-of-Life", sequence=3,
required_framework="EU-BATTERY-REG")
# Milestones for each checkpoint
acc.add_milestone("MS-cell-qc", "PH-manufacturing", "Cell QC",
required_procedures=["HBOM-INV.1", "HBOM-SUPPLY.1", "DPP-CHRG.1"])
acc.add_milestone("MS-module-assy", "PH-manufacturing", "Module Assembly",
required_procedures=["HBOM-THERM.1", "HBOM-LIFE.1", "DPP-SOH.1"])
acc.add_milestone("MS-pack-integ", "PH-integration", "Pack Integration",
required_procedures=["DPP-SOH.1", "HBOM-THERM.1", "HBOM-INV.1"])
acc.add_milestone("MS-vehicle-integ", "PH-integration", "Vehicle Integration",
required_procedures=["DPP-SOH.1", "DPP-CHRG.1"])
acc.add_milestone("MS-field-ops", "PH-operation", "Field Operation",
required_procedures=["DPP-CHRG.1", "DPP-DEGRAD.1", "DPP-SOH.1"],
min_attestation_count=10) # Field ops needs ongoing evidence
acc.add_milestone("MS-second-life", "PH-eol", "Second Life Assessment",
required_procedures=["DPP-SOH.1", "DPP-DEGRAD.1", "HBOM-LIFE.1"])
acc.add_milestone("MS-recycling", "PH-eol", "Recycling Handoff",
required_procedures=["DPP-EOL.1", "HBOM-SUPPLY.1"])
# Record attestations as inspections happen
# Checkpoint 1: Cell QC in Erfurt
acc.add_leaf("MS-cell-qc", "a1b2c3d4e5f6", "HBOM-INV.1", verdict="PASS")
acc.add_leaf("MS-cell-qc", "b2c3d4e5f6a1", "HBOM-SUPPLY.1", verdict="PASS")
acc.add_leaf("MS-cell-qc", "c3d4e5f6a1b2", "DPP-CHRG.1", verdict="PASS")
# Checkpoint 2: Module Assembly in Wroclaw
acc.add_leaf("MS-module-assy", "d4e5f6a1b2c3", "HBOM-THERM.1", verdict="PASS")
acc.add_leaf("MS-module-assy", "e5f6a1b2c3d4", "HBOM-LIFE.1", verdict="PASS")
acc.add_leaf("MS-module-assy", "f6a1b2c3d4e5", "DPP-SOH.1", verdict="PASS")
# Check manufacturing phase gate before shipping to France
gate = acc.check_gate("PH-manufacturing")
print(f"Manufacturing gate: {'OPEN' if gate['passed'] else 'BLOCKED'}")
# Manufacturing gate: OPEN
# The structure root reflects all evidence so far
print(f"Structure root: {acc.structure_root}")
# Generate a proof for any single attestation
proof = acc.get_multi_tier_proof("a1b2c3d4e5f6")
# Anyone can verify offline -- no access to the full tree needed
verified = verify_multi_tier_proof("a1b2c3d4e5f6", proof)
print(f"Proof verified: {verified}") # Trueimport {
MilestoneAccumulator,
verifyMultiTierProof
} from "@tenova/swt3-ai/milestone-merkle";
const acc = new MilestoneAccumulator("ST-ebg-2026-0417");
// Define phases
acc.addPhase("PH-manufacturing", "Manufacturing", 0);
acc.addPhase("PH-integration", "Integration", 1);
acc.addPhase("PH-operation", "Operation", 2);
acc.addPhase("PH-eol", "End-of-Life", 3);
// Define milestones (checkpoints)
acc.addMilestone("MS-cell-qc", "PH-manufacturing", "Cell QC",
["HBOM-INV.1", "HBOM-SUPPLY.1", "DPP-CHRG.1"]);
acc.addMilestone("MS-module-assy", "PH-manufacturing", "Module Assembly",
["HBOM-THERM.1", "HBOM-LIFE.1", "DPP-SOH.1"]);
acc.addMilestone("MS-pack-integ", "PH-integration", "Pack Integration",
["DPP-SOH.1", "HBOM-THERM.1", "HBOM-INV.1"]);
// Record attestations
acc.addLeaf("MS-cell-qc", "a1b2c3d4e5f6", "HBOM-INV.1", "PASS");
acc.addLeaf("MS-cell-qc", "b2c3d4e5f6a1", "HBOM-SUPPLY.1", "PASS");
acc.addLeaf("MS-cell-qc", "c3d4e5f6a1b2", "DPP-CHRG.1", "PASS");
// Check gate
const gate = acc.checkGate("PH-manufacturing");
console.log(gate.passed ? "GATE_OPEN" : "GATE_BLOCKED");
// Verify any attestation offline
const proof = acc.getMultiTierProof("a1b2c3d4e5f6");
if (proof) {
console.log(verifyMultiTierProof("a1b2c3d4e5f6", proof)); // true
}For production systems, the battery management platform integrates directly with the SWT3 API. All endpoints require Bearer authentication (axm_* API key or session token).
POST /api/v1/merkle/milestone
Content-Type: application/json
Authorization: Bearer axm_live_...
{
"action": "create",
"name": "Battery Pack EBG-2026-0417",
"domain": "battery-dpp",
"phases": [
{
"name": "Manufacturing",
"milestones": [
{
"name": "Cell QC",
"required_procedures": ["HBOM-INV.1", "HBOM-SUPPLY.1", "DPP-CHRG.1"]
},
{
"name": "Module Assembly",
"required_procedures": ["HBOM-THERM.1", "HBOM-LIFE.1", "DPP-SOH.1"]
}
]
},
{
"name": "Integration",
"milestones": [
{
"name": "Pack Integration",
"required_procedures": ["DPP-SOH.1", "HBOM-THERM.1", "HBOM-INV.1"]
},
{
"name": "Vehicle Integration",
"required_procedures": ["DPP-SOH.1", "DPP-CHRG.1"]
}
]
},
{
"name": "Operation",
"milestones": [
{
"name": "Field Operation",
"required_procedures": ["DPP-CHRG.1", "DPP-DEGRAD.1", "DPP-SOH.1"],
"min_attestation_count": 10
}
]
},
{
"name": "End-of-Life",
"milestones": [
{
"name": "Second Life Assessment",
"required_procedures": ["DPP-SOH.1", "DPP-DEGRAD.1", "HBOM-LIFE.1"]
},
{
"name": "Recycling Handoff",
"required_procedures": ["DPP-EOL.1", "HBOM-SUPPLY.1"]
}
]
}
]
}POST /api/v1/merkle/milestone
Content-Type: application/json
Authorization: Bearer axm_live_...
{
"action": "add_leaf",
"milestone_id": "MS-...",
"fingerprint": "a1b2c3d4e5f6",
"procedure_id": "DPP-SOH.1",
"verdict": "PASS",
"clearing_level": 1
}GET /api/v1/merkle/milestone/gate?phase_id=PH-...
Authorization: Bearer axm_live_...
Response:
{
"ok": true,
"phase_id": "PH-manufacturing",
"passed": true,
"gate_status": "GATE_OPEN",
"gate_fingerprint": "g7h8i9j0k1l2",
"failing_milestones": [],
"unresolved_fails": [],
"missing_procedures": []
}GET /api/v1/merkle/milestone/proof?fingerprint=a1b2c3d4e5f6&structure_id=ST-ebg-2026-0417
Authorization: Bearer axm_live_...
Response:
{
"ok": true,
"proof": {
"fingerprint": "a1b2c3d4e5f6",
"milestone_root": "...",
"phase_root": "...",
"structure_root": "...",
"boundaries": [
{"from_tier": "milestone", "to_tier": "phase", "transition_hash": "..."},
{"from_tier": "phase", "to_tier": "structure", "transition_hash": "..."}
],
"total_steps": 7
}
}The DPP evidence chain is not just for the manufacturer. Four downstream actors need to verify it:
A German market surveillance authority inspecting EuroBatt's products requests the structure root for a specific battery pack. They then pull multi-tier proofs for specific attestations to verify that cell-level QC was performed in Germany with valid procedures. The authority does not need access to the Polish or French evidence. The proof resolves to the same structure root.
A stationary storage company in the Netherlands evaluates this battery for repurposing. They query the DPP evidence chain and verify: (1) the full degradation history via DPP-DEGRAD.1 attestations, (2) the most recent SoH via DPP-SOH.1, (3) whether the Manufacturing and Integration gates passed cleanly or were overridden. A battery with a clean gate history and predictable degradation is a better candidate for second life.
For Second-Life Operators
Request the multi-tier proof for the most recent DPP-SOH.1 attestation. Verify it resolves to the current structure root. Then request the DPP-DEGRAD.1 attestation history for the Field Operation milestone. The degradation pattern (gradual vs. sudden, thermal vs. calendar aging) directly affects the battery's suitability for stationary storage and its expected remaining useful life.
The recycler in Antwerp receives the battery at end of life. Before processing, they verify the complete lifecycle chain: was every checkpoint completed? Were any gates overridden? What materials were documented in the HBOM-SUPPLY.1 attestations? The material composition data in the DPP directly affects the recycling process selection.
For Recyclers
The HBOM-SUPPLY.1 attestation from Checkpoint 1 documents the cathode chemistry (NMC 811, NMC 622, LFP, etc.). This determines the hydrometallurgical or pyrometallurgical process selection. Verify this attestation is present and that its fingerprint resolves to the structure root. If the material composition data is missing or unverifiable, the recycler must perform independent material analysis before processing -- adding cost and delay.
When the recycler in Antwerp receives a battery, they must verify they have the correct battery and formally accept custody in the evidence chain. The handoff procedure has four steps:
Assessor Note
The recycler's DPP-EOL.1 attestation must include a disposition code identifying the recycling pathway (hydrometallurgical, pyrometallurgical, direct recycling). Verify that the disposition code is consistent with the cathode chemistry from HBOM-SUPPLY.1. An NMC 811 battery processed via direct recycling without pre-treatment is a process safety finding.
An independent auditor verifying the battery's carbon footprint declaration (Art. 7) traces the evidence chain from raw material sourcing (Checkpoint 1, HBOM-SUPPLY.1) through manufacturing energy consumption, transportation between countries, and end-of-life processing. Each stage's carbon-relevant data is embedded in the attestation factors. The auditor does not need to trust any single party's claim. Each claim is cryptographically bound to the attestation at the time it was made.
Assessor Note
For Art. 7 carbon footprint verification, focus on the HBOM-SUPPLY.1 attestations across all checkpoints. The supply chain provenance data must cover cobalt, lithium, nickel, and natural graphite sourcing. If any raw material source is undocumented, the carbon footprint declaration is incomplete. Cross-reference the HBOM-SUPPLY.1 timestamps with the manufacturer's due diligence report (Art. 11) to verify that due diligence was performed before the materials entered the production line.
| Standard | Relationship |
|---|---|
| EN 18286 (QMS for AI) | Quality management system for AI. SWT3 provides the runtime evidence that demonstrates EN 18286 conformity for AI-driven battery management systems (BMS predictive algorithms, degradation models). |
| ISO 42001 (AIMS) | AI management system. If the BMS uses AI for SoH prediction or degradation modeling, ISO 42001 Annex A controls map to SWT3 AI procedures. See the ISO 42001 Implementation Evidence Guide. |
| EU Machinery Regulation 2023/1230 | Applies to battery manufacturing equipment. Phased process witnessing can extend to the production line itself. See the EU Machinery Regulation Crosswalk. |
| IEC 62619 | Safety requirements for secondary lithium cells. IEC 62619 test results can be witnessed as attestation leaves in the Cell QC milestone, creating a cryptographic link between safety certification and the DPP. |
| CSRD (ESRS E1/E5) | Corporate sustainability reporting. The same HBOM-SUPPLY.1 and DPP-CHRG.1 attestations that populate the DPP also feed into CSRD environmental reporting under ESRS E1 (climate) and E5 (resource use). |
| EU CBAM | Carbon Border Adjustment Mechanism. For batteries with non-EU material inputs, the HBOM-SUPPLY.1 embedded carbon data supports CBAM-adjacent reporting requirements. |
Cross-reference: For HBOM procedure details and battery passport fundamentals, see the HBOM and EU Battery Passport Guide. For the underlying phased process witnessing engine, see Phased Process Witnessing.