prEN IEC 62973-4:2025

SLOVENSKI STANDARD
01-december-2025
Železniške naprave - Vozna sredstva - Baterije za pomožne močnostne napajalne
sisteme - 4. del: Sekundarne zatesnjene nikelj-kovinske hidridne baterije
Railway applications – Rolling stock – Batteries for auxiliary power supply systems – Part
4: Secondary sealed nickel-metal hydride batteries
Bahnanwendungen - Fahrzeuge - Batterien für Bordnetzversorgungssysteme – Teil 4:
Gasdichte Nickel-Metallhydrid-Sekundärbatterien
Applications ferroviaires - Matériel roulant -Batteries pour systèmes d'alimentation
auxiliaire - Partie 4: Batterie d'accumulateurs nickel-hydrure métallique étanche
Ta slovenski standard je istoveten z: prEN IEC 62973-4:2025
ICS:
29.220.99 Drugi členi in baterije Other cells and batteries
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD DRAFT
prEN IEC 62973-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2025
ICS 45.060.01 -
English Version
Railway applications - Rolling stock - Batteries for auxiliary
power supply systems - Part 4: Secondary sealed nickel-metal
hydride batteries
(IEC 62973-4:2021)
Applications ferroviaires - Matériel roulant -Batteries pour Bahnanwendungen - Fahrzeuge - Batterien für
systèmes d'alimentation auxiliaire - Partie 4: Batterie Bordnetzversorgungssysteme - Teil 4: Gasdichte Nickel-
d'accumulateurs nickel-hydrure métallique étanche Metallhydrid-Sekundärbatterien
(IEC 62973-4:2021) (IEC 62973-4:2021)
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2026-01-02.

The text of this draft consists of the text of IEC 62973-4:2021 (9/2638(F)/FDIS).

If this draft becomes a European Standard, 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.

This draft European Standard was established by CENELEC 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,
Türkiye and the United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.

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.
Project: 81986 Ref. No. prEN IEC 62973-4:2025 E

European foreword
This document (prEN IEC 62973-4:2025) consists of the text of IEC 62973-4:2021 prepared by IEC/TC 9
"Electrical equipment and systems for railways".
This document is currently submitted to the Enquiry.
The following dates are proposed:
• latest date by which the existence of this document has (doa) dav+ 6 months
to be announced at national level
• latest date by which this document has to be (dop) dav+ 12 months
implemented at national level by publication of an
identical national standard or by endorsement
• latest date by which the national standards conflicting (dow) dav+ 36 months
with this document have to be withdrawn (to be confirmed or
modified when voting)
This document is read in conjunction with EN 62675, EN IEC 63115-1 and EN IEC 63115-2.
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 60051 series Direct acting indicating analogue electrical EN 60051 series
measuring instruments and their
accessories
IEC 60077-1 - Railway applications - Electric equipment EN 60077-1 -
for rolling stock - Part 1: General service
conditions and general rules
IEC 62485-2 - Safety requirements for secondary EN IEC 62485-2 -
batteries and battery installations - Part 2:
Stationary batteries
IEC 62675 - Secondary cells and batteries containing EN 62675 -
alkaline or other non-acid electrolytes -
Sealed nickel-metal hydride prismatic
rechargeable single cells
IEC 62902 2019 Secondary cells and batteries - Marking EN IEC 62902 2019
symbols for identification of their chemistry
IEC 62973-1 2018 Railway applications - Rolling stock - EN IEC 62973-1 —
Batteries for auxiliary power supply
systems - Part 1: General Requirements
IEC 63115-1 2020 Secondary cells and batteries containing EN IEC 63115-1 2020
alkaline or other non-acid electrolytes -
Sealed nickel-metal hydride cells and
batteries for use in industrial applications -
Part 1: Performance
IEC 63115-2 2021 Secondary cells and batteries containing EN IEC 63115-2 2021
alkaline or other non-acid electrolytes -
Sealed nickel-metal hydride cells and
batteries for use in industrial applications -
Part 2: Safety
Under preparation. Stage at the time of publication: prEN IEC 62973-1:2025.
IEC 62973-4 ®
Edition 1.0 2021-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Railway applications – Rolling stock – Batteries for auxiliary power supply

systems –
Part 4: Secondary sealed nickel-metal hydride batteries

Applications ferroviaires – Materiel roulant –Batteries pour systemes

d'alimentation auxiliaire –
Partie 4: Batterie d'accumulateurs nickel-hydrure métallique étanche

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 45.060.01 ISBN 978-2-8322-9279-2

– 2 – IEC 62973-4:2021 © IEC 2021
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 9
4 General requirements . 9
4.1 Definitions of components of a battery system (images are examples) . 9
4.2 Definition of battery type . 10
4.2.1 General . 10
4.2.2 Cell designation . 10
4.2.3 Prismatic cells . 10
4.2.4 Cylindrical cells . 10
4.3 Environmental conditions . 10
4.3.1 Battery system . 10
4.3.2 Battery module . 10
4.4 System requirements . 11
4.4.1 System voltage . 11
4.4.2 Charging requirements . 12
4.4.3 Discharging requirements . 15
4.4.4 Charge retention (self-discharge) . 16
4.4.5 Requirements for battery capacity sizing. 16
4.5 Safety and protection requirements . 17
4.5.1 General . 17
4.5.2 Deep discharge of batteries . 17
4.5.3 Temperature compensation during charging . 17
4.6 Fire protection . 17
4.7 Maintenance . 17
5 Mechanical design of battery system . 17
6 Electrical interface . 18
7 Markings. 18
7.1 Safety signs . 18
7.2 Nameplate . 18
7.2.1 General . 18
7.2.2 Battery modules and cells . 18
8 Storage and transportation conditions . 18
8.1 Transportation . 18
8.2 Storage of battery . 18
9 Testing . 19
9.1 General . 19
9.2 Parameter measurement tolerances . 19
9.3 Type test . 20
9.3.1 General . 20
9.3.2 Electrical characteristic tests . 20
9.3.3 Dielectric test . 21
9.3.4 Load profile test . 21

IEC 62973-4:2021 © IEC 2021 – 3 –
9.3.5 Shock and vibration test . 21
9.3.6 Reliability test . 21
9.4 Routine test . 21
9.4.1 General . 21
9.4.2 Visual checks . 21
9.4.3 Dielectric test . 21
9.4.4 Measurement of open circuit voltage . 22
9.4.5 Measurement of Internal resistance .
...