EN IEC 62660-3:2022

Secondary lithium-ion cells for the propulsion of electric road vehicles - Part 3: Safety requirements

This part of IEC 62660 specifies test procedures and acceptance criteria for safety performance of secondary lithium-ion cells and cell blocks used for propulsion of electric vehicles (EV) including battery electric vehicles (BEV) and hybrid electric vehicles (HEV). This document determines the basic safety performance of cells used in a battery pack and system under intended use and reasonably foreseeable misuse or incident, during the normal operation of the EV. The safety requirements of the cell in this document are based on the premise that the cells are properly used in a battery pack and system within the limits for voltage, current and temperature as specified by the cell manufacturer (cell operating region). The evaluation of the safety of cells during transport and storage is not covered by this document. NOTE 1 The safety performance requirements for lithium-ion battery packs and systems are defined in ISO 6469‑1. The specifications and safety requirements for lithium-ion battery packs and systems of electrically propelled mopeds and motorcycles are defined in ISO 18243. IEC 62619 covers the safety requirements for the lithium-ion cells and batteries for industrial applications, including, for example, forklift trucks, golf carts, and automated guided vehicles. NOTE 2 Lithium cells, modules, battery packs, and battery systems are regulated by International Air Transport Association (IATA) and International Maritime Organization (IMO) for air and sea transport, and, regionally, by other authorities, mainly for land transport. Refer to IEC 62281 for additional information.

Lithium-Ionen-Sekundärzellen für den Antrieb von Elektrostraßenfahrzeugen - Teil 3: Sicherheitsanforderungen

Eléments d'accumulateurs lithium-ion pour la propulsion des véhicules routiers électriques - Partie 3: Exigences de sécurité

IEC 62660-3:2022 est disponible sous forme de IEC 62660-3:2022 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L'IEC 62660-3:2022 spécifie les procédures d'essai et les critères d'acceptation en matière de performance de sécurité des éléments d'accumulateurs lithium-ion et des blocs d'éléments utilisés pour la propulsion des véhicules électriques (VE), y compris les véhicules électriques à batterie (VEB) et les véhicules électriques hybrides (VEH). Le présent document a pour objet de déterminer les performances de sécurité de base des éléments utilisés dans un groupe et système de batteries dans les conditions d'utilisation prévue et les mauvaises utilisations ou incidents raisonnablement prévisibles, pendant le fonctionnement normal du VE. Dans le présent document, les exigences de sécurité de l'élément s'appuient sur l'hypothèse selon laquelle les éléments sont correctement utilisés dans un groupe et système de batteries dans les limites de tension, de courant et de température spécifiées par le fabricant de l'élément (plage de fonctionnement de l'élément).

Sekundarni litij-ionski členi za pogon električnih cestnih vozil - 3. del: Varnostne zahteve

Ta del standarda IEC 62660 določa preskusne postopke in merila sprejemljivosti za varnostne lastnosti sekundarnih litij-ionskih členov in blokov členov, ki se uporabljajo za pogon električnih vozil (EV), vključno z električnimi akumulatorskimi vozili (BEV) ali hibridnimi električnimi vozili (HEV).
Ta dokument je namenjen za določanje osnovnih varnostnih lastnosti členov v akumulatorju in sistemu v skladu s predvideno uporabo ter pričakovano nepravilno uporabo ali incidentom pri običajnem delovanju električnih vozil. Varnostne zahteve za člen v tem dokumentu temeljijo na predpostavki, da se členi pravilno uporabljajo v akumulatorju ter sistemu znotraj napetostnih, tokovnih in temperaturnih omejitev, ki jih določi proizvajalec členov (območje delovanja členov).
Ta dokument ne vključuje ocene varnosti za člene med prevozom in skladiščenjem.
OPOMBA 1: Varnostne zahteve glede zmogljivosti litij-ionskih akumulatorjev in sistemov so opredeljene v standardu ISO 6469-1. Specifikacije in varnostne zahteve za litij-ionske akumulatorje ter sisteme električno gnanih mopedov in motornih koles so opredeljene v standardu ISO 18243. IEC 62619 zajema varnostne zahteve za litij-ionske člene in akumulatorje za industrijsko uporabo, vključno z viličarji, vozički za golf in avtomatsko vodenimi vozili.
OPOMBA 2: Informacije o območju delovanja členov so podane v dodatku A.

General Information

• Status: Published
• Publication Date: 14-Apr-2022
• ICS: 29.220.20 - Acid secondary cells and batteries
• ICS: 43.120 - Electric road vehicles
• Technical Committee: CLC/TC 21X - Secondary cells and batteries
• Drafting Committee: IEC/TC 21 - IEC_TC_21
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 15-Apr-2022
• Completion Date: 15-Apr-2022
• Ref Project: SIST EN IEC 62660-3:2022 - Secondary lithium-ion cells for the propulsion of electric road vehicles - Part 3: Safety requirements

Relations

• Replaces: EN 62660-3:2016 - Secondary lithium-ion cells for the propulsion of electric road vehicles - Part 3: Safety requirements
• Effective Date: 19-Apr-2022

Overview

EN IEC 62660-3:2022 - Secondary lithium‑ion cells for the propulsion of electric road vehicles - Part 3: Safety requirements is the CLC-adopted European version of IEC 62660‑3 (Edition 2, 2022). It specifies test procedures and acceptance criteria to evaluate the safety performance of secondary lithium‑ion cells and cell blocks used for propulsion in electric road vehicles (EVs), including battery electric vehicles (BEV) and hybrid electric vehicles (HEV). The standard defines basic safety performance under intended use and reasonably foreseeable misuse or incidents when cells are used within the manufacturer‑specified operating region (voltage, current, temperature). Transport and storage safety evaluation are excluded.

Key topics and technical requirements

EN IEC 62660‑3:2022 focuses on practical, reproducible safety tests and criteria. Major technical topics include:

• Test conditions and measurement requirements: instrumentation, tolerances, thermal stabilization and electrical measurement procedures (capacity, SOC adjustment).
• Mechanical safety tests: mechanical shock and crush tests to assess cell integrity under mechanical abuse.
• Thermal tests: high‑temperature endurance and temperature‑cycling to evaluate thermal resilience and stability.
• Electrical abuse tests: external short‑circuit, overcharge, forced discharge and internal short‑circuit tests. The 2022 edition adds an alternative internal short‑circuit test and revises overcharge test conditions.
• Acceptance criteria: pass/fail conditions that define acceptable safety performance for cells and cell blocks.
• Operating region guidance: normative/informative annexes that illustrate safe charging/discharging zones and considerations for voltage and temperature limits.

The edition removes the previous vibration test and documents new or updated methods (e.g., Annex C alternative internal short‑circuit procedure).

Applications and typical users

This standard is used to verify and demonstrate the safety of lithium‑ion cells for vehicle propulsion. Typical users include:

• Cell manufacturers validating design and safety performance
• EV OEMs and battery pack/system integrators for component selection and system safety validation
• Test laboratories and certification bodies performing conformity and type‑approval testing
• Safety engineers and compliance teams preparing documentation for regulatory approval or supplier contracts
• R&D teams assessing failure modes and improving cell robustness against mechanical, thermal and electrical abuse

Common applications: product development testing, supplier qualification, safety certification, and informing battery management system (BMS) limits and pack‑level safety design.

Related standards

Relevant complementary documents referenced in EN IEC 62660‑3:2022 include:

• IEC 62660‑1 / IEC 62660‑2 (cell performance and reliability for EV propulsion)
• ISO 6469‑1 (battery pack/system safety performance)
• ISO 18243 (mopeds/motorcycles battery requirements)
• IEC 62619 (industrial battery safety)
• IEC 62281, IATA and IMO guidance (transport and storage regulations)
• IEC 62133‑2, IEC 61434 (harmonized safety standards)

Keywords: EN IEC 62660-3:2022, lithium‑ion cells safety, EV battery safety, BEV, HEV, internal short‑circuit test, overcharge test, crush test, thermal testing, battery pack safety.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2022
Nadomešča:
SIST EN 62660-3:2017
Sekundarni litij-ionski členi za pogon električnih cestnih vozil - 3. del: Varnostne
zahteve
Secondary lithium-ion cells for the propulsion of electric road vehicles - Part 3: Safety
requirements
Lithium-Ionen-Sekundärzellen für den Antrieb von Elektrostraßenfahrzeugen - Teil 3:
Sicherheitsanforderungen
Eléments d'accumulateurs lithium-ion pour la propulsion des véhicules routiers
électriques - Partie 3: Exigences de sécurité
Ta slovenski standard je istoveten z: EN IEC 62660-3:2022
ICS:
29.220.20 Kislinski sekundarni členi in Acid secondary cells and
baterije batteries
43.120 Električna cestna vozila Electric road vehicles
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62660-3

NORME EUROPÉENNE
EUROPÄISCHE NORM April 2022
ICS 29.220.20; 43.120 Supersedes EN 62660-3:2016 and all of its amendments
and corrigenda (if any)
English Version
Secondary lithium-ion cells for the propulsion of electric road
vehicles - Part 3: Safety requirements
(IEC 62660-3:2022)
Eléments d'accumulateurs lithium-ion pour la propulsion Lithium-Ionen-Sekundärzellen für den Antrieb von
des véhicules routiers électriques - Partie 3: Exigences de Elektrostraßenfahrzeugen - Teil 3:
sécurité Sicherheitsanforderungen
(IEC 62660-3:2022) (IEC 62660-3:2022)
This European Standard was approved by CENELEC on 2022-04-05. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62660-3:2022 E

European foreword
The text of document 21/1133/FDIS, future edition 2 of IEC 62660-3, prepared by IEC/TC 21
"Secondary cells and batteries" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 62660-3:2022.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2023-01-05
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2025-04-05
document have to be withdrawn
This document supersedes EN 62660-3:2016 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 62660-3:2022 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 61434 NOTE Harmonized as EN 61434
IEC 62133-2 NOTE Harmonized as EN 62133-2
IEC 62660-1 NOTE Harmonized as EN IEC 62660-1
ISO 18243 NOTE Harmonized as EN ISO 18243
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
1 2
IEC 62619 — Secondary cells and batteries containing EN IEC 62619 —
alkaline or other non-acid electrolytes -
Safety requirements for secondary lithium
cells and batteries, for use in industrial
applications
IEC 62660-2 2018 Secondary lithium-ion cells for the propulsion EN IEC 62660-2 2019
of electric road vehicles - Part 2: Reliability
and abuse testing
ISO/TR 8713 - Electrically propelled road vehicles - - -
Vocabulary
Second edition under preparation. Stage at the time of publication: IEC FDIS 62619:2021.
Under preparation. Stage at the time of publication: FprEN IEC 62619:2021.
IEC 62660-3 ®
Edition 2.0 2022-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Secondary lithium-ion cells for the propulsion of electric road vehicles –

Part 3: Safety requirements
Éléments d’accumulateurs lithium-ion pour la propulsion des véhicules routiers

électriques –
Partie 3: Exigences de sécurité

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.220.20; 43.120 ISBN 978-2-8322-1083-3

– 2 – IEC 62660-3:2022 © IEC 2022
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Test conditions . 9
4.1 General . 9
4.2 Measuring instruments . 9
4.2.1 Range of measuring devices . 9
4.2.2 Voltage measurement . 9
4.2.3 Current measurement . 9
4.2.4 Temperature measurements . 9
4.2.5 Other measurements . 10
4.3 Tolerance . 10
4.4 Thermal stabilization . 10
5 Electrical measurement . 10
5.1 General charge conditions . 10
5.2 Capacity . 11
5.3 SOC adjustment . 11
6 Safety tests . 11
6.1 General . 11
6.2 Mechanical tests . 12
6.2.1 Mechanical shock . 12
6.2.2 Crush . 12
6.3 Thermal test . 13
6.3.1 High temperature endurance. 13
6.3.2 Temperature cycling . 13
6.4 Electrical tests . 14
6.4.1 External short-circuit . 14
6.4.2 Overcharge . 14
6.4.3 Forced discharge . 14
6.4.4 Internal short-circuit test . 15
Annex A (informative) Operating region of cells for safe use . 17
A.1 General . 17
A.2 Charging conditions for safe use . 17
A.2.1 General . 17
A.2.2 Consideration on charging voltage . 17
A.2.3 Consideration on temperature . 18
A.3 Example of operating region . 19
Annex B (informative) Explanation for the internal short-circuit test . 20
B.1 General concept . 20
B.2 Internal short-circuit caused by the particle contamination . 20
Annex C (normative) Alternative internal short-circuit test (6.4.4.2.2) . 22
C.1 General . 22
C.2 Test preparation and test set-up . 22
C.2.1 Preparation of cell before the test . 22

IEC 62660-3:2022 © IEC 2022 – 3 –
C.2.2 Test setup . 24
C.2.3 Preliminary test . 25
C.3 Test procedure . 26
C.4 Acceptance criteria . 26
Bibliography . 27

Figure 1 – Example of temperature measurement of cell . 10
Figure 2 – Example of crush test . 13
Figure A.1 – An example of operating region for charging of typical lithium-ion cells . 19
Figure A.2 – An example of operating region for discharging of typical lithium-ion cells . 19
Figure C.1 – Example of case thinning . 22
Figure C.2 – Example of thinning tool . 23
Figure C.3 – Example of removing hard case . 23
Figure C.4 – Example of hard case removal method during cell manufacturing . 23
Figure C.5 – Example of fixation of cell . 24
Figure C.6 – Test setup image for voltage measurement . 24
Figure C.7 – Example of abrupt voltage drop . 25

Table B.1 – Examples of the internal short-circuit of cell . 20

– 4 – IEC 62660-3:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SECONDARY LITHIUM-ION CELLS FOR THE PROPULSION
OF ELECTRIC ROAD VEHICLES –
Part 3: Safety requirements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 62660-3 has been prepared by IEC technical committee 21: Secondary cells and batteries.
It is an International Standard.
This second edition cancels and replaces the first edition published in 2016. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The new method for the internal short-circuit test has been added in 6.4.4.2.2 and Annex C,
as an alternative option to the test in 6.4.4.2.1.
b) The vibration test has been deleted.
c) The test conditions of overcharge (6.4.2.2) have been partially revised.

IEC 62660-3:2022 © IEC 2022 – 5 –
The text of this International Standard is based on the following documents:
Draft Report on voting
21/1133/FDIS 21/1137/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts in the IEC 62660 series, published under the general title Secondary lithium-ion
cells for the propulsion of electric road vehicles, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

– 6 – IEC 62660-3:2022 © IEC 2022
SECONDARY LITHIUM-ION CELLS FOR THE PROPULSION
OF ELECTRIC ROAD VEHICLES –
Part 3: Safety requirements
1 Scope
This part of IEC 62660 specifies test procedures and acceptance criteria for safety performance
of secondary lithium-ion cells and cell blocks used for propulsion of electric vehicles (EV)
including battery electric vehicles (BEV) and hybrid electric vehicles (HEV).
This document determines the basic safety performance of cells used in a battery pack and
system under intended use and reasonably foreseeable misuse or incident, during the normal
operation of the EV. The safety requirements of the cell in this document are based on the
premise that the cells are properly used in a battery pack and system within the limits for voltage,
current and temperature as specified by the cell manufacturer (cell operating region).
The evaluation of the safety of cells during transport and storage is not covered by this
document.
NOTE 1 The safety performance requirements for lithium-ion battery packs and systems are defined in ISO 6469‑1.
The specifications and safety requirements for lithium-ion battery packs and systems of electrically propelled mopeds
and motorcycles are defined in ISO 18243. IEC 62619 covers the safety requirements for the lithium-ion cells and
batteries for industrial applications, including, for example, forklift trucks, golf carts, and automated guided vehicles.
NOTE 2 Lithium cells, modules, battery packs, and battery systems are regulated by International Air Transport
Association (IATA) and International Maritime Organization (IMO) for air and sea transport, and, regionally, by other
authorities, mainly for land transport. Refer to IEC 62281 for additional information.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 62619:— , Secondary cells and batteries containing alkaline or other non-acid electrolytes
– Safety requirements for secondary lithium cells and batteries, for use in industrial applications
IEC 62660-2:2018, Secondary lithium-ion cells for the propulsion of electric road vehicles –
Part 2: Reliability and abuse testing
ISO/TR 8713, Electrically propelled road vehicles – Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TR 8713 and the
following apply.
___________
Second edition under preparation. Stage at the time of publication: IEC FDIS 62619:2021.

IEC 62660-3:2022 © IEC 2022 – 7 –
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
BEV
battery electric vehicle
electric vehicle with only a traction battery as power source for vehicle propulsion
3.2
cell block
group of cells connected together in parallel configuration with or without protective devices
(e.g. fuse or positive temperature coefficient resistor (PTC)) and not yet fitted with its final
housing, terminal arrangement or electronic control device
3.3
cylindrical cell
cell with a cylindrical shape in which the overall height is equal to or greater than the diameter
[SOURCE: IEC 60050-482:2004, 482-02-39]
3.4
explosion
failure that occurs when a cell container opens violently and its solid contents are forcibly
expelled
3.5
fire
emission of flames from a cell or cell block for more than 1 s
Note 1 to entry: Sparks and arcing are not considered as flames.
3.6
HEV
hybrid electric vehicle
vehicle with both a rechargeable energy storage system and a fuelled power source for
propulsion
3.7
internal short-circuit
unintentional electrical connection between the negative and positive electrodes inside a cell
3.8
leakage
visible escape of liquid electrolyte from a part, except for a vent, such as the case, sealing part,
and/or terminals of the cell
3.9
nominal voltage
suitable approximate value of the voltage used to designate or identify a cell
[SOURCE: IEC 60050-482:2004, 482-03-31, modified – Deletion of "a battery or an
electrochemical system" at the end of the definition.]

– 8 – IEC 62660-3:2022 © IEC 2022
3.10
pouch cell
cell having the shape of a parallelepiped whose faces are rectangular and with a prismatic
flexible laminate film case
3.11
prismatic cell
cell having the shape of a parallelepiped whose faces are rectangular and with a prismatic hard
case
[SOURCE: IEC 60050-482:2004, 482-02-38, modified − The word "cell" has been added to the
term, "qualifies a cell or a battery" has been replaced with "cell" in the definition, and "and with
a prismatic hard case housing" has been added.]
3.12
rated capacity
C
n
capacity value of a cell in ampere hours (Ah) determined under specified conditions and
declared by the cell manufacturer
Note 1 to entry: The subscript n in C is the time base in hours (h). In this document, n = 3 for BEV application and
n
n = 1 for HEV application unless otherwise specified.
Note 2 to entry: Term and definition based on IEC 60050-482:2004, 482-03-15.
3.13
reference test current
I
t
reference test current in amperes (A) which is expressed as
I = C / 1
t n
Note 1 to entry: 1 has a dimension of time in hours (h).
Note 2 to entry: See IEC 61434:1996, Clause 2.
3.14
rupture
mechanical failure of a container case of a cell induced by an internal or external cause,
resulting in exposure or spillage but not ejection of materials
3.15
secondary lithium-ion cell
secondary single cell whose electrical energy is derived from the insertion/extraction reactions
of lithium-ions between the negative electrode and the positive electrode
Note 1 to entry: A secondary cell is a manufactured unit providing a source of electrical energy by direct conversion
of chemical energy. The cell consists of electrodes, electrolyte, container, terminals and, if any, separators. The
electrode can be monopolar or bipolar; the current collector of the former has active material of single polarity and
the latter has positive and negative electrode active materials. The electrolyte includes an ionic conductive liquid or
solid, or a mixture of them. The cell is designed to be charged electrically.
Note 2 to entry: Where the term "cell" is used alone in this document, it refers to a secondary lithium-ion cell.
3.16
SOC
state of charge
quantity of electricity stored in a cell expressed as a percentage of rated capacity

IEC 62660-3:2022 © IEC 2022 – 9 –
3.17
upper limit charging voltage
highest charging voltage in the cell operating region, which is specified by the cell manufacturer
Note 1 to entry: Information on the cell operating region is provided in Annex A.
[SOURCE: IEC 62133-2:2017, 3.19, modified − Note to entry added.]
3.18
venting
release of excessive internal pressure from a cell in a manner intended by design to preclude
rupture or explosion
4 Test conditions
4.1 General
Unless otherwise stated in this document, cells shall be tested at room temperature. For the
purposes of this document, room temperature is 25 °C ± 2 K.
The details of the instrumentation used shall be provided in any report of results.
Cell blocks can be tested as an alternative to cells in accordance with the agreement between
the cell manufacturer and the customer.
Concerning the cell for plug-in hybrid electric vehicles (PHEV), the cell manufacturer can select
either the test condition of BEV application or of HEV application.
NOTE Test and measurement can be conducted in a fixture as recommended by the cell manufacturer.
4.2 Measuring instruments
4.2.1 Range of measuring devices
The instruments used shall enable the values of voltage and current to be measured. The range
of these instruments and measuring methods shall be chosen so as to ensure the accuracy
specified for each test.
For analogue instruments, this implies that the readings shall be taken in the last third of the
graduated scale.
Any other measuring instruments may be used provided they give an equivalent accuracy.
4.2.2 Voltage measurement
The resistance of the voltmeters used shall be at least 1 MΩ/V.
4.2.3 Current measurement
The entire assembly of ammeter, shunt and leads shall be of an accuracy class of 0,5 or better.
4.2.4 Temperature measurements
The cell temperature shall be measured by use of a surface temperature measuring device
capable of an equivalent scale definition and accuracy of calibration as specified in 4.2.1. The
temperature should be measured at a location which most closely reflects the cell or cell block
temperature. The temperature may be measured at additional appropriate locations, if
necessary.
– 10 – IEC 62660-3:2022 © IEC 2022
The examples for temperature measurement are shown in Figure 1. The instructions for
temperature measurement specified by the cell manufacturer shall be followed.

Figure 1 – Example of temperature measurement of cell
4.2.5 Other measurements
Other values may be measured by use of a measuring device, provided it complies with 4.3.
4.3 Tolerance
The overall accuracy of controlled or measured values, relative to the specified or actual values,
shall be within the following tolerances:
a) ±0,1 % for voltage;
b) ±1 % for current;
c) ±2 K for temperature;
d) ±0,1 % for time;
e) ±0,1 % for mass;
f) ±0,1 % for dimensions.
These tolerances comprise the combined accuracy of the measuring instruments, the
measurement technique used, and all other sources of error in the test procedure.
4.4 Thermal stabilization
For the stabilization of cell temperature, the cell shall be soaked to a specified ambient
temperature for a minimum of 12 h. This period may be reduced if thermal stabilization is
reached. Thermal stabilization is considered to be reached if after one interval of 1 h, the
change of cell temperature is lower than 1 K.
5 Electrical measurement
5.1 General charge conditions
Unless otherwise stated in this document, prior to the electrical measurement, the cell shall be
charged as follows.
IEC 62660-3:2022 © IEC 2022 – 11 –
Prior to charging, the cell shall be discharged at room temperature at a constant current of
1/3 I (A) for BEV application and 1 I (A) for HEV application down to an end-of-discharge
t t
voltage specified by the cell manufacturer. Then, the cell shall be charged at room temperature
according to the charging method declared by the cell manufacturer.
5.2 Capacity
Before the SOC adjustment in 5.3, the capacity of the test cell shall be confirmed to be the
rated value in accordance with the following phases.
1) Phase 1 – The cell shall be charged in accordance with 5.1. After charge, the cell
temperature shall be stabilized in accordance with 4.4.
2) Phase 2 – The cell shall be discharged at room temperature at a constant current of
1/3 I (A) for BEV application and at 1 I
...