| Quality Management System | Whether the manufacturing site operates a controlled quality management system. | Valid ISO 9001:2015 certificate, certificate scope, issuing body, expiration date, and latest surveillance or recertification result. | The certificate should cover the relevant battery-pack design, assembly, testing, or manufacturing activities at the audited site. ISO 9001 certification should not be treated as proof of a specific battery performance level. | High |
| Document and Change Control | How engineering, process, software, and component changes are reviewed and released. | Controlled drawings, bill of materials, engineering-change notices, approval records, revision history, and customer notification procedures. | No uncontrolled work instructions or obsolete drawings should be available at production stations. Changes affecting cells, protection circuits, firmware, welding, or enclosure design should receive documented technical review. | High |
| Incoming Cell Inspection | Whether incoming cells are verified before use rather than accepted only from supplier paperwork. | Incoming inspection plans, sampling records, cell-lot documentation, supplier certificates of analysis, visual inspection records, and quarantine procedures. | Inspection should cover part number, chemistry, dimensions, polarity, packaging condition, date or lot code, open-circuit voltage, and electrical screening defined by the product specification. | High |
| Cell Traceability | Whether each production batch can be linked to the source cell lot and manufacturing records. | Serialized or batch-coded records connecting cell lot, receiving date, production order, operator, workstation, test results, and shipment. | The supplier should be able to demonstrate backward traceability from a finished pack to the cell lot and forward traceability from a cell lot to affected finished packs. Retention periods should meet contractual and applicable regulatory requirements. | High |
| Cell Matching Controls | How cells are grouped to reduce imbalance within a parallel or series-connected pack. | Matching procedure, calibrated equipment records, test temperature, measurement method, sampling plan, and pass/fail limits for voltage, internal resistance, and capacity. | Acceptance limits must be defined by the pack design and cell datasheet. A supplier should not rely on visual matching alone; electrical matching should be recorded for the cells used in each pack or module. | High |
| Voltage and Internal-Resistance Screening | Whether cell measurements are repeatable and performed under controlled conditions. | Equipment calibration certificates, measurement-system records, test fixtures, temperature-control records, and sample test reports. | Measurement methods should specify rest time, temperature, instrument resolution, contact condition, and allowable variation. Limits should be product-specific rather than copied across different cell chemistries. | High |
| Capacity Verification | Whether capacity claims are confirmed using a defined charge, discharge, and rest procedure. | Capacity-test specifications, cycler calibration records, representative test curves, test duration, cutoff-voltage settings, and nonconformance records. | Test conditions should be consistent with the cell manufacturer’s rated conditions or the approved product specification. Any reduced sampling plan should be justified by risk analysis and historical process capability. | High |
| Battery Management System | Whether the protection and monitoring functions are verified for the specific battery configuration. | BMS requirements, firmware revision records, overcharge and over-discharge tests, over-current tests, temperature-protection tests, balancing verification, and communication checks. | Protection thresholds and balancing behavior should be documented, tested, and linked to the approved cell chemistry, series count, parallel count, operating temperature, and charger specification. | High |
| Welding and Electrical Interconnection | Whether cell connections are produced consistently without damaging cells or creating high-resistance joints. | Welding parameters, first-article records, pull-test or peel-test results where applicable, electrode maintenance logs, fixture checks, and visual inspection criteria. | Critical welding parameters should be locked or access-controlled. Defect examples should cover incomplete welds, excessive spatter, misalignment, damaged insulation, and unacceptable joint resistance. | High |
| Process Control and Operator Training | Whether assembly steps are standardized and performed by qualified personnel. | Work instructions, process flow charts, control plans, operator training records, competency assessments, and line-audit results. | Operators should be trained for polarity control, electrostatic discharge precautions, insulation placement, torque control, connector handling, and safe handling of charged cells. | Medium |
| End-of-Line Testing | Whether every finished pack receives the required functional and safety checks. | Automated test records, serial-number linkage, test limits, tester calibration, insulation-resistance results, voltage readings, BMS communication results, and final visual inspection. | Finished-pack test results should be automatically associated with the pack serial number or production identifier. Failed units should be blocked from shipment until disposition is formally approved. | High |
| Safety and Compliance Testing | Whether the product is evaluated against applicable transport, cell, pack, and end-use requirements. | Applicable test reports and declarations, including UN 38.3 transport-test evidence and relevant battery safety standards such as IEC 62133-2 where applicable. | Reports should identify the tested configuration, cell chemistry, electrical ratings, model or revision, test laboratory, and report status. Documentation should match the actual production design. | High |
| Nonconforming Product Control | How defects, suspect cells, rework, and customer returns are controlled. | Nonconformance reports, containment actions, rework instructions, concession approvals, root-cause analysis, and corrective-action effectiveness checks. | Suspect cells and packs should be physically segregated and electronically blocked where possible. Reworked packs should receive documented reinspection and complete safety testing before release. | High |
| Supplier and Subcontractor Control | Whether critical external processes and component suppliers are monitored. | Approved supplier list, supplier audits, incoming-quality trends, corrective-action records, and controls for cells, BMS boards, connectors, fuses, housings, and chargers. | Critical components should have defined specifications and change-notification requirements. A supplier should be able to identify the source and revision of safety-critical components used in a finished pack. | Medium |
| Data Integrity and Record Access | Whether production and test records are complete, protected, and retrievable. | Electronic quality records, access permissions, audit trails, backup procedures, data-retention policy, and sample retrieval demonstrations. | Records should be legible, time-stamped, protected from unauthorized alteration, and retrievable by pack serial number, production order, or cell lot within a reasonable time. | Medium |
| Continuous Improvement | Whether the supplier uses quality data to reduce recurring defects and variation. | First-pass yield, defect-per-million or defect-rate trends, customer-return analysis, process capability studies, internal-audit findings, and improvement actions. | The supplier should show trend-based corrective actions rather than isolated short-term fixes. Recurring issues involving imbalance, weld defects, BMS faults, or insulation damage should have documented owners and due dates. | Medium |
