ISO 6469-1:2019/Amd 1:2022

INTERNATIONAL ISO
STANDARD 6469-1
Third edition
2019-04
AMENDMENT 1
2022-11
Electrically propelled road vehicles —
Safety specifications —
Part 1:
Rechargeable energy storage system
(RESS)
AMENDMENT 1: Safety management of
thermal propagation
Véhicules routiers électriques — Spécifications de sécurité —
Partie 1: Système de stockage d'énergie rechargeable (RESS)
AMENDEMENT 1: Management de la sécurité de la propagation
thermique
Reference number
ISO 6469-1:2019/Amd.1:2022(E)
ISO 6469-1:2019/Amd.1:2022(E)
© ISO 2022
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Published in Switzerland
ii
ISO 6469-1:2019/Amd.1:2022(E)
Foreword
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bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
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electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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on the ISO list of patent declarations received (see www.iso.org/patents).
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 37,
Electrically propelled vehicles.
A list of all parts in the ISO 6469 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iii
ISO 6469-1:2019/Amd.1:2022(E)
Electrically propelled road vehicles — Safety
specifications —
Part 1:
Rechargeable energy storage system (RESS)
AMENDMENT 1: Safety management of thermal propagation

Introduction
Insert a new clause “Introduction” as follows:
With the rapid development of the electric vehicle industry, its core component, the rechargeable
energy storage system (RESS), has increasingly attracted attention, especially the safety
requirements of RESS have raised a large interest within the public. This document specifies the
general safety requirements for the RESS of electrically propelled road vehicles.
This document also focuses on the safety performance of the lithium-ion battery. One central safety
issue for lithium-ion battery systems is the potential for propagation of a thermal runaway event
due to a cell thermal failure. For this purpose, this document provides methods for testing thermal
runaway risk mitigation to support the development of vehicle and system safety concepts.
The document primarily provides a tool kit for vehicle and RESS manufacturers to evaluate their
product safety in terms of thermal propagation. It should enable RESS and/or vehicle manufacturers
to get a deeper knowledge of the system behaviour in case of an internal failure of a single cell.
Combined tests on cell and system level based on this document will provide comparable results
about the RESS safety.
Since it does not contain neither pass or fail criteria for thermal propagation, it is not foreseen to be
used for homologation purposes.

Scope
Add the following paragraph after the first paragraph.
Specifically, for lithium-ion based RESS, this document specifies demonstration methods for
thermal runaway risk mitigation in case of a cell failure leading to an internal short circuit,
including the collection of associated data. It also specifies a selection of different test methods for
thermal propagation. The selected tests can be carried out at vehicle level or for RESS and RESS
subsystem if appropriate.
Terms and definitions
Add the following additional terminological entries in Clause 3:
3.31
functional unit
entity of hardware or software, or both, capable of accomplishing a specified purpose
[SOURCE: ISO/IEC 2382:2015, 2121310, modified — Notes to entry were removed.]
ISO 6469-1:2019/Amd.1:2022(E)
3.32
internal short circuit
isolation failure inside a cell
Note 1 to entry: Formation of internal short circuits in a single cell may have different causes. The severity of
the internal short circuit depends on the nature of the short and what parts of the cell that are involved. Some
examples of potential causes of internal short circuit to consider are listed below:
— manufacturing defect involving foreign object debris (i.e. particles deposited on the electrode surfaces
during cell manufacturing);
— manufacturing defect due to misalignment of electrode active material and separator;
— separator pinholes and creasing;
— separator shrinkage;
— electronically conductive burrs;
— current collector insulation flaws;
— lithium metal deposition at charging due to intercalation limitations;
— copper corrosion and formation of copper dendrites during cell operation;
— mechanical deformation of the cell, e.g. denting of the cell packaging during manufacture or deformation of
the electrode coil or stack resulting from cycling.
3.33
operational design domain
specific operating domain(s) in which the RESS (3.22) is designed to operate, including but not limited
to voltage/SOC (3.26) range, current range, temperature range, environmental conditions, and other
domain constraints
3.34
safety case for thermal propagation of the RESS
argument that the safety requirements for the RESS (3.22) are complete and satisfied by evidence
compiled from the work product of the safety activities during development
Note 1 to entry: Safety case for thermal propagation (3.37) of the RESS means in this document that a logical
and hierarchical set of work products that describe risks in terms of hazards presented by the RESS in case
of an internal short circuit (3.32) and the subsequent thermal energy release within the RESS, and which sets
expectations and guidance for future performance, if hazards are controlled successfully.
3.35
target cell
cell in which thermal runaway (3.38) is initiated
3.36
thermal event
condition (event which occurs) when the temperature within RESS (3.22) rises significantly or is higher
than the maximum operating temperature (3.17) as defined by the supplier (3.27) or customer (3.6)
Note 1 to entry: Depending on the situation (e.g. amount of heat generation compared to heat dissipation) a
thermal event may or may not lead to a thermal runaway (3.38).
3.37
thermal propagation
transfer of thermal energy generated from thermal runaway (3.38) of a single cell to adjacent cells, which
results in the thermal runaway of other cells in a RESS (3.22) or any assembly of RESS components
ISO 6469-1:2019/Amd.1:2022(E)
3.38
thermal runaway
heat generation caused by uncontrolled exothermic reactions inside the cell

Clause 5
Add a new subclause after 5.6 as follows:
5.7  Thermal propagation requirements
5.7.1  General
Thermal propagation requirements apply only to a lithium-ion RESS or RESS subsystem used for the
propulsion of electric vehicles. Internal short circuit is a condition that can cause thermal runaway in
a cell with subsequent thermal propagation in a RESS or RESS subsystem and which is not considered
in other standards. Internal short circuit can be caused by contamination through the manufacturing
process, by several events during operation and by aging (see 3.32).
The variety of lithium-ion technologies and the different cell construction types do not allow the
definition of one single test method that covers all conditions in a safe, comparable, and reproducible
way. This document provides three approaches to evaluate safety performance against thermal
propagation for a RESS or RESS subsystem.
5.7.2  Safety performance of RESS
Safety performance of a RESS or RESS sub-system shall be considered by one of the following
approaches:
1) demonstrating system robustness against a thermal failure of one cell to limit or withstand
propagation effects by choosing test methods as specified in 6.7;
2) employing appropriate detection systems to identify early markers indicating a latent fault in a cell
and demonstrate risk mitigation by the system safety approach detailed in Clause 7.

Clause 6
Add the following subclauses after 6.6 as follows:
6.7  Thermal propagation test
6.7.1  General
This subclause provides test methods to demonstrate the behaviour of a RESS or RESS subsystem in
case of internal short circuit or thermal runaway caused by failure of a single cell. It also provides the
test methods to generate measurement data which can be used to evaluate the safety performance of
a RESS or RESS subsystem. The test method should be selected according to the intended test purpose
and the possibilities for implementing the trigger method. Installation of a second trigger source may
be performed by the test agency but is not required. A guidance for method selection based on cell type
and test cases is given in Table 9.
ISO 6469-1:2019/Amd.1:2022(E)
Table 9 — Guidance for method selection
Trigger Applicable cell Application at Application at Application at Remarks
method type (limita- RESS subsys- RESS level vehicle level
tions provided tem level
in relevant
clauses)
Internal Any cell type Yes Yes Yes Cell manufacture is the only
heater one to be able to introduce the
internal heater inside the cell
before electrolyte filling.
Localized Any cell type Yes Yes Yes Heating element parameter
rapid exter- may vary depending on differ-
nal heating ent battery chemistries or cell
type choices
Nail pene- Any cell type Yes Yes Yes This trigger method cannot
tration be applied to any position in a
RESS or RESS subsystem. Can
only be applied to the cells
located in the outer perimeter
of the pack.
NOTE 1 All trigger methods have intrinsic limitations and are state-of-the-art. Additional trigger methods can
be developed as appropriate.
NOTE 2 These test methods are developed for lithium-ion RESS and vehicles using such RESS but are also
applicable to other battery chemistries and future electric vehicle energy storage technologies and lithium-
ion technology for other applications/industries. Using these methods outside of existing lithium-ion battery
chemistries or manufacturing methods for electric vehicles, requires further validation to determine the
suitability of the method is necessary.
If not otherwise specified, the tests described apply to the RESS or RESS subsystem referred to as
device under test (DUT) in the following text. All methods utilize the initiation of thermal runaway in a
target cell.
6.7.2  Target cell selection
For target cell selection, the number of adjacent cells, cell packaging, and the distance between cells
in proximity to the potential target cell shall be considered. Installation of a trigger for the chosen
target cell shall not impede the functionality of the original cell or RESS design and its safety features,
such as venting, cooling, battery management system, gas permeability, spacing between cells or other
components and thermal barriers.
In the field, a single cell thermal runaway may occur in any cell location within the RESS. For externally
applied triggers, force may be required to maintain the method in proximity to the target cell and this
may dictate the choice of the target cell. Target cell selection should follow a worst-case scenario in
terms of thermal propagation.
Examples of conditions to consider are:
— thermal couplings to other cells and to RESS cooling mechanisms;
— thermal insulation around cells;
— geometrical aspect of electrical configuration, e.g. series or parallel connections;
— venting paths inside the RESS;
— configuration of battery management sensors and sampling rate.
ISO 6469-1:2019/Amd.1:2022(E)
Determination of the worst-case scenario may require preliminary tests, calculations or analysis,
considering RESS or RESS subsystem design, cell capacity/chemistry/designs, or cooling system.
The selection of a single cell within the DUT depends on the chosen trigger method and the RESS design
and shall be agreed between the customer and supplier.
If the intended application scenario is deemed not to have been covered by the tests, then repeating
the test procedure with cells in different locations that represent the likely thermal environments and
relationships within the RESS may be considered.
NOTE Placing the chosen trigger between battery cells using the existing RESS construction is sufficient but
placing the trigger on an edge cell requires additional support
...