Overview
ISO 6469-1:2019/Amd 1:2022 is an ISO amendment that extends Part 1 of ISO 6469 (Rechargeable Energy Storage System - RESS) to address safety management of thermal propagation in electrically propelled road vehicles. The amendment provides a practical toolkit of definitions, test methods and evidence criteria that help manufacturers and test laboratories evaluate how a lithium‑ion RESS responds when a single‑cell failure (internal short circuit) leads to thermal runaway and possible propagation to adjacent cells. It is intended to support design-level risk assessment and safety cases, not as a pass/fail homologation standard.
Key technical topics and requirements
- Definitions & concepts: Adds terms such as internal short circuit, thermal event, thermal runaway, thermal propagation, target cell, functional unit, and operational design domain to establish a common vocabulary for RESS thermal safety.
- Three test trigger methods (Table 9):
- Internal heater (inside cell) - applicable where cell manufacture allows insertion.
- Localized rapid external heating - heating element applied externally.
- Nail penetration - mechanical trigger; limited to accessible/perimeter cells.
- Notes that each trigger has intrinsic limitations and choice depends on cell chemistry and pack design.
- Target cell selection: Guidance to select worst‑case cell locations considering thermal coupling, cooling, venting paths, geometrical configuration, and BMS sensor placement.
- Test conditions & preconditioning: Specifies environmental conditions (temperature, humidity, pressure), state‑of‑charge (SOC) protocols (charge to test SOC; discharge at 0.2·ItA where applicable), and requirement that thermal/BMS systems be operational during vehicle/pack tests.
- Evidence criteria for thermal runaway: Quantitative indicators for occurrence:
- For cells <130 Wh/kg: e.g., dT/dt > 1 K/s with temperature exceeding manufacturer’s onset temperature lasting >3 s (or equivalent combinations with venting/voltage drop).
- For cells ≥130 Wh/kg: e.g., dT/dt > 15 K/s with temperature exceeding onset temperature lasting >0.5 s (or equivalent combinations).
- Post‑test analysis: Guidance on disassembly observations (ejected solids, BMS faults, logged errors) as supporting evidence for thermal runaway.
- Safety approaches: Two principal routes - demonstrate system robustness against propagation (tests in Clause 6.7) or implement early‑detection systems and a safety case per Clause 7.
Practical applications and who uses it
- Vehicle OEMs & RESS manufacturers: design validation, pack layout, thermal management and barrier strategies, supplier test agreements.
- Battery system integrators & safety engineers: develop safety cases for thermal propagation, select worst‑case scenarios, and optimize BMS detection/mitigation.
- Independent test laboratories: perform standardized propagation tests and generate comparable measurement data.
- Regulators and certification bodies (informational): use as reference for understanding test methods and evidence even though the amendment does not set homologation pass/fail criteria.
Related standards (context)
- ISO 6469 series (other parts of RESS safety)
- IEC and sector standards referenced for energy density calculation and battery test methods (e.g., IEC 62660‑1)
Keywords: ISO 6469-1:2019/Amd 1:2022, thermal propagation, RESS safety, thermal runaway, lithium‑ion battery, internal short circuit, battery testing, electric vehicle battery safety, target cell, BMS, state of charge.
Open preview (PDF)Electrically propelled road vehicles — Safety specifications — Part 1: Rechargeable energy storage system (RESS) — Amendment 1: Safety management of thermal propagation
