SIST EN IEC 62933-4-3:2026

SLOVENSKI STANDARD
01-marec-2026
Električne naprave za shranjevanje energije (EES) - 4-3. del: Zahteve za zaščito
sistemov za shranjevanje energije na osnovi baterij (BESS) glede na okoljske
razmere (IEC 62933-4-3:2025)
Electrical energy storage (EES) systems - Part 4-3: Protection requirements of battery-
based energy storage systems (BESS) according to environmental conditions (IEC
62933-4-3:2025)
Elektrische Energiespeichersysteme (EES) - Teil 4-3: Die Schutzanforderungen von
BESS entsprechend den Umweltbedingungen und Standorttypen (IEC 62933-4-3:2025)
Systèmes de stockage de l’énergie électrique (EES) - Partie 4-3: Exigences de
protection des systèmes de stockage de l’énergie sur batterie (BESS) en fonction des
conditions environnementales (IEC 62933-4-3:2025)
Ta slovenski standard je istoveten z: EN IEC 62933-4-3:2025
ICS:
13.020.30 Ocenjevanje vpliva na okolje Environmental impact
assessment
27.010 Prenos energije in toplote na Energy and heat transfer
splošno engineering in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62933-4-3

NORME EUROPÉENNE
EUROPÄISCHE NORM November 2025
ICS 13.020.30; 27.010
English Version
Electrical energy storage (EES) systems - Part 4-3: Protection
requirements of battery-based energy storage systems (BESS)
according to environmental conditions
(IEC 62933-4-3:2025)
Systèmes de stockage de l'énergie électrique (EES) - Partie Elektrische Energiespeichersysteme (EES) - Teil 4-3: Die
4-3: Exigences de protection des systèmes de stockage de Schutzanforderungen von BESS entsprechend den
l'énergie sur batterie (BESS) en fonction des conditions Umweltbedingungen und Standorttypen
environnementales (IEC 62933-4-3:2025)
(IEC 62933-4-3:2025)
This European Standard was approved by CENELEC on 2025-11-24. 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.
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Türkiye 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
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62933-4-3:2025 E

European foreword
The text of document 120/419/FDIS, future edition 1 of IEC 62933-4-3, prepared by TC 120 "Electrical
Energy Storage (EES) systems" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 62933-4-3:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-11-30
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-11-30
document have to be withdrawn
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 62933-4-3:2025 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 standard indicated:
IEC 62477-1:2022 NOTE Approved as EN IEC 62477-1:2023 (not modified)
IEC 62606:2013 NOTE Approved as EN 62606:2013
ISO 9999:2022 NOTE Approved as EN ISO 9999:2022 (not modified)
ISO 13702:2024 NOTE Approved as EN ISO 13702:2024 (not modified)
ISO 14001:2015 NOTE Approved as EN ISO 14001:2015 (not modified)
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.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 62933-1 2024 Electrical energy storage (EES) systems - EN IEC 62933-1 2024
Part 1: Vocabulary
IEC 62933-4-3 ®
Edition 1.0 2025-10
INTERNATIONAL
STANDARD
Electrical energy storage(EES) systems -
Part 4-3: Protection requirements of battery-based energy storage systems
(BESS) according to environmental conditions
ICS 13.020.30; 27.010 ISBN 978-2-8327-0623-7

IEC 62933-4-3:2025-10(en)
IEC 62933-4-3:2025 © IEC 2025
CONTENTS
FOREWORD . 2
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General . 7
5 Environmental factors of BESS . 7
5.1 Analysis of the factors to affect BESS . 7
5.2 The types and origin of the environmental factors . 8
6 Risk analysis of each environmental factor and relevant measures . 9
6.1 Risks on BESS from water and relevant measures . 9
6.2 Risks on BESS from the air and relevant measures . 10
6.3 Risks on BESS from flora and relevant measures . 12
6.4 Risks on BESS from fauna and relevant measures. 12
6.5 Risks on BESS from lightning and relevant measures . 13
6.6 Risks on BESS from seismic events and relevant measures . 13
6.7 Risks on BESS from other disasters and relevant measures . 14
Annex A (informative) Report format of risk analysis and the measures . 15
Bibliography . 16

Figure 1 – Assumed BESS architecture . 8

Table 1 – Example of environmental factors on BESS . 8
Table 2 – Risks from water and protection measures . 9
Table 3 – Risks from air and protection measures . 10
Table 4 – Risks from flora and protection measures . 12
Table 5 – Risks from Fauna including human and protection measures . 13
Table 6 – Risks from lightning and protection measures. 13
Table 7 – Risks from vibration and protection measures . 14
Table 8 – Risks from other disasters and protection measures . 14
Table A.1 – Example of a report describing impacts on BESS and related protection
measures . 15

IEC 62933-4-3:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Electrical energy storage (EES) systems -
Part 4-3: Protection requirements of battery-based energy storage
systems (BESS) according to environmental conditions

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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 62933-4-3 has been prepared by IEC technical committee TC120: Electrical Energy
Storage (EES) systems. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
120/419/FDIS 120/433/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.
IEC 62933-4-3:2025 © IEC 2025
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/publications.
A list of all parts in the IEC 62933 series, published under the general title Electrical energy
storage (EES) systems, 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, or
• revised.
IEC 62933-4-3:2025 © IEC 2025
INTRODUCTION
According to reports over the world, BESS have been influenced by environmental and climatic
conditions of the areas where they are installed. The BESS can be particularly affected by
temperature, humidity, and vibration and natural disasters. In order to minimize the impacts,
this document is expected to be of great help in stable installation and operation by presenting
the causes, risk factors and the appropriate measures for each environmental condition when
installing the BESS.
IEC 62933-4-3:2025 © IEC 2025
1 Scope
This part of IEC 62933 applies to the effects of the environmental conditions on battery-based
energy storage systems (BESS). This document addresses these effects and identifies causes,
chains of events and final effects on the BESS. Based on those effects, preventative or
mitigating measures are described. Typical environmental effects on the BESS include, but are
not limited to, the effects of lightning, seismic activities, water, air, flora, fauna, and humans.
The described measures focus on the entire BESS including all power and communication
connections and their point of connections (POCs).
The scope of this document is limited to BESS specific requirements and operating conditions.
Specific design or safety requirements of individual BESS subsystems are excluded from this
document.
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 62933-1:2024, Electrical energy storage (EES) systems - Part 1: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62933-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
environmental factor
physical, social and attitudinal environment in which people live and conduct their lives
[SOURCE: ISO 9999:2022, 3.7]
3.2
risk analysis
systematic use of available information to identify hazards and to estimate the risk
[SOURCE: ISO/IEC Guide 51:2014, 3.10]
3.3
seismic action
action caused by earthquake ground motions
[SOURCE: ISO 2394:2015, 2.3.15]
3.4
human factors
environmental, organisational, and job factors that influence behaviour of work in a way that
can affect health and safety outcomes including the performance of critical safety systems
IEC 62933-4-3:2025 © IEC 2025
[SOURCE: ISO 13702:2024, 3.26]
3.5
arcing
luminous discharge of electricity across an insulating medium, usually accompanied by the
partial volatilization of the electrodes
Note 1 to entry: A complete sinusoidal current half-cycle is not considered to be an arcing half-cycle.
[SOURCE: IEC 62606:2013, 3.1, modified – the preferred term “arc” has been removed.]
3.6
internal resistance
opposition to the flow of current within a cell or a battery, that is, sum of electronic resistance
and ionic resistance with the contribution to total effective resistance including
inductive/capacitive properties
[SOURCE: ISO 17546:2024, 3.17]
3.7
battery management system
BMS
set of protection functions associated with a battery to prevent overcharge, overcurrent, over-
temperature, under-temperature and, if applicable, overdischarge and which monitors and/or
manages its state, calculates secondary data, reports that data and/or controls its environment
to influence the battery’s safety, performance and/or service life’
[SOURCE: IEC 63056:2020, 3.12, modified – the notes have been removed.]
3.8
water leakage
water drop or flow that spills out from the closed pipe and container
[SOURCE: ISO 2710-2:2019, 3.4.37]
3.9
electromagnetic compatibility
EMC
ability of equipment or a system to function satisfactorily in its electromagnetic environment
without introducing intolerable electromagnetic disturbances to anything in that environment
[SOURCE: IEC 60050-161:2018,161-01-07]
3.10
high voltage
voltage having a value above a conventionally adopted limit
Note 1 to entry: An example is the set of upper voltage values used in bulk power systems.
[SOURCE: IEC 60050-151:2001, 151-15-05]
3.11
salinity
quantification of any dissolved salts in water, expressed as either a percentage or a
concentration
[SOURCE: ISO/TR 12748:2015, 2.50]
IEC 62933-4-3:2025 © IEC 2025
3.12
stem
portion of a standing tree above ground, excluding branches
[SOURCE: ISO 8965:2022, 3.4.1]
3.13
mould
woolly or powdery fungal growth that can form on the surface of wood in damp conditions
[SOURCE: ISO 24294:2021, 13.17]
3.14
point of connection
POC
reference point on the electric power system where an EES system is connected
[SOURCE: IEC 62933-1:2024, 4.1.3, modified – the note has been removed.]
4 General
The impact on battery energy storage systems (BESS) from environmental factors depends on
the location of the BESS installation. This document provides guidelines on the environmental
factors and requirements for identifying potential impacts on BESS installed in the described
environmental areas.
When a BESS operator or system integrator installs the system in a specified area, the
environmental factors are analysed and documented in accordance with Clause 5 and Clause 6
together with an example shown in Annex A before the BESS is installed at a designated area.
The environmental factors referenced in this document are in accordance with
IEC TS 62933-4-1. IEC TS 62933-4-1:2017, 6.3, identifies environmental factors such as
lightning, seismic risk, flooding, water, rain, temperature, pressure, wind, ice and snow, life
form invasion, vibration/resonance, dust, smoke, fire, external fire, external electromagnetic
source, humidity, salt mist/salt water/erosive chemical, corrosion, solar irradiation, sediment
build up. Clause 5 categorizes these factors based on IEC TS 62933-4-1 and classifies them
with detailed risk factors.
Clause 5 and Clause 6 describe the risk analysis of each environmental factor and the relevant
measures. The relevant measures are examples and not limited to the ones listed.
5 Environmental factors of BESS
5.1 Analysis of the factors to affect BESS
BESS are installed and operated around the world for various purposes. When they are installed
in many different areas, the factors which are listed in IEC TS 62933-4-1, can have an effect
on the BESS. In this document, the typical environmental effects on the BESS include, but are
not limited to, the effects of lightning, seismic activities, water, air, flora, fauna, and humans. In
order to operate the BESS stably, it is important to address the problems that can arise due to
these factors and take the appropriate measures to solve the problems.
This document describes the types of environmental factors and the ways they adversely affect
the BESS.
The assumed BESS architecture shown in Figure 1 is used for the risk analysis in Clause 6.
IEC 62933-4-3:2025 © IEC 2025
Figure 1 – Assumed BESS architecture
The operator or system integrator of the BESS should refer to the environmental factors
described in this document. The risk analysis and related measures shall be performed prior to
the installation.
5.2 The types and origin of the environmental factors
According to 5.1, the environmental factors listed are lightning, seismic activities, water, air,
flora, fauna, and humans. Each factor can take on different forms, but this is not an exhaustive
list.
...