prEN IEC 62973-2:2025/prAA:2026
(Amendment)Railway applications - Rolling stock - Batteries for auxiliary power supply systems - Part 2: Nickel Cadmium (NiCd) batteries
General Information
- Abstract
The part 2 of IEC 62973 will get a European annex. The European annex will contain additions regarding European operating conditions (such as temperature) and requirements (such as such as discharging/charging characteristic, application of guidelines TR 50718) as well as general additions (which are contained in EN 50547 and are missing in the IEC-version).
- Status
- Not Published
- Publication Date
- 13-Mar-2028
- Technical Committee
- CLC/TC 9X - Electrical and electronic applications for railways
- Drafting Committee
- WG 45 - RS - Auxiliary Batteries
- Current Stage
- 4020 - Enquiry circulated - Enquiry
- Start Date
- 07-Aug-2026
- Due Date
- 26-Jan-2026
- Completion Date
- 07-Aug-2026
Overview
prEN IEC 62973-2:2025/prAA:2026 outlines the requirements for Nickel Cadmium (NiCd) batteries used in auxiliary power supply systems on railway rolling stock. Developed by CLC/TC 9X and currently in draft status, this standard contains essential additions geared toward European operating conditions and requirements, aligning with established guidelines such as EN 50547 and CLC/TR 50718. It specifies performance expectations for NiCd batteries under the demanding conditions present in European railway operations, such as variations in temperature and specific charging/discharging profiles, supporting safe and reliable power delivery for critical onboard systems.
Key Topics
- Scope and Application: Targets NiCd batteries for auxiliary power on rolling stock within the European railway sector. Addresses real-world operational conditions and harmonizes with European regulatory expectations.
- Technical Additions: Introduces definitions, charging requirements, system voltage limits, capacity sizing, fire protection, and guidelines for battery information systems as tailored for Europe.
- Environmental and Safety Requirements: Recognizes the significance of temperature variation, capacity retention, self-discharge, and fire risk. Ensures compliance with CLC/TR 50718 and related documents.
- Battery Performance: Details charging characteristics, temperature correction for charging voltages, and aging factors to enhance battery life and safety in railway environments.
- Sizing and Design: Specifies methods for determining necessary battery capacity, considering aging, extreme temperatures, and emergency load requirements.
- Information Systems: Addresses limitations and methodologies for monitoring available energy in NiCd batteries due to their unique discharge behavior.
Applications
This standard is vital for a wide range of stakeholders in the European railway sector:
- Rolling Stock Manufacturers: Ensures battery systems meet robust European standards for reliability, safety, and environmental resilience.
- System Integrators: Facilitates the integration of NiCd battery solutions in compliance with both IEC and European-specific requirements, especially for auxiliary systems critical to rolling stock operation.
- Battery Manufacturers: Provides clear benchmarks for designing, testing, and documenting NiCd products for the railway market, accounting for unique environmental and operational demands.
- Maintenance and Engineering Teams: Offers practical guidance for battery sizing, ongoing performance monitoring, and end-of-life assessment.
Adhering to this standard supports improved system uptime, passenger safety, and cost-effective long-term maintenance for railway operators.
Related Standards
To ensure comprehensive compliance and robust design, the following related standards should be consulted alongside prEN IEC 62973-2:2025/prAA:2026:
- EN 50125-1: Environmental conditions for railway rolling stock and on-board equipment.
- EN 50155: Electronic equipment used on rolling stock, including operational voltage and climatic requirements.
- CLC/TR 50718: Guidelines for using EN 45545-2 related to fire safety requirements for NiCd batteries on rolling stock.
- IEC 61434: Guide for the designation of current in alkaline secondary cell and battery standards.
- prEN IEC 62973-3:2025: Specifies requirements for lead acid batteries in auxiliary railway applications.
By integrating these standards, organizations can ensure their NiCd battery systems are not only compliant with current regulations but also optimized for reliability, safety, and performance within the European rail sector.
Keywords: railway applications, rolling stock, NiCd batteries, auxiliary power supply, European standard, battery performance, charging requirements, battery capacity sizing, fire protection, environmental conditions, CLC/TR 50718, EN 50155, onboard railway systems.
Relations
- Effective Date
- 25-Feb-2025
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Frequently Asked Questions
prEN IEC 62973-2:2025/prAA:2026 is a draft published by CLC. Its full title is "Railway applications - Rolling stock - Batteries for auxiliary power supply systems - Part 2: Nickel Cadmium (NiCd) batteries". This standard covers: The part 2 of IEC 62973 will get a European annex. The European annex will contain additions regarding European operating conditions (such as temperature) and requirements (such as such as discharging/charging characteristic, application of guidelines TR 50718) as well as general additions (which are contained in EN 50547 and are missing in the IEC-version).
The part 2 of IEC 62973 will get a European annex. The European annex will contain additions regarding European operating conditions (such as temperature) and requirements (such as such as discharging/charging characteristic, application of guidelines TR 50718) as well as general additions (which are contained in EN 50547 and are missing in the IEC-version).
prEN IEC 62973-2:2025/prAA:2026 is classified under the following ICS (International Classification for Standards) categories: 29.220.99 - Other cells and batteries; 45.060.01 - Railway rolling stock in general. The ICS classification helps identify the subject area and facilitates finding related standards.
prEN IEC 62973-2:2025/prAA:2026 has the following relationships with other standards: It is inter standard links to prEN IEC 62973-2:2025. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
prEN IEC 62973-2:2025/prAA:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2026
Železniške naprave - Vozna sredstva - Baterije za pomožne napajalne sisteme - 2.
del: Nikelj-kadmij (NiCd) baterije - Dopolnilo AA
Railway applications - Rolling stock - Batteries for auxiliary power supply systems - Part
2: Nickel Cadmium (NiCd) batteries
Bahnanwendungen - Fahrzeuge - Batterien für Bordnetzversorgungssysteme - Teil 2:
Nickel-Cadmium-Batterien (NiCd-Batterien)
Applications ferroviaires - Matériel roulant - Batteries pour systèmes d'alimentation
auxiliaire - Partie 2: Batteries au Nickel Cadmium (NiCd)
Ta slovenski standard je istoveten z: prEN IEC 62973-2:2025/prAA:2026
ICS:
29.220.99 Drugi členi in baterije Other cells and batteries
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
oSIST prEN IEC 62973- en
2:2025/oprAA:2026
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD DRAFT
prEN IEC 62973-2:2025
NORME EUROPÉENNE
EUROPÄISCHE NORM
prAA
August 2026
ICS 45.060.01; 29.220.99 -
English Version
Railway applications - Rolling stock - Batteries for auxiliary
power supply systems - Part 2: Nickel Cadmium (NiCd) batteries
Applications ferroviaires - Matériel roulant - Batteries pour Bahnanwendungen - Fahrzeuge - Batterien für
systèmes d'alimentation auxiliaire - Partie 2: Batteries au Bordnetzversorgungssysteme - Teil 2: Nickel-Cadmium-
Nickel Cadmium (NiCd) Batterien (NiCd-Batterien)
This draft amendment prAA, if approved, will modify the European Standard prEN IEC 62973-2:2025; it is submitted to CENELEC members
for enquiry.
Deadline for CENELEC: 2026-10-30.
It has been drawn up by CLC/TC 9X.
If this draft becomes an amendment, CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this amendment the status of a national standard without any alteration.
This draft amendment 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
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 81134 Ref. No. prEN IEC 62973-2:2025/prAA:2026 E
1 Contents Page
2 European foreword . 3
3 1 Modification to Clause 2, “Normative references” . 4
4 2 Modification to 3.1, “Terms and definitions” . 4
5 3 Modification to 3.2, “Abbreviated terms” . 4
6 4 Modification to 4.2.5, “Pocket plate/electrode technology” . 4
7 5 Modification to 4.4.1, “System voltage” . 4
8 6 Modification to 4.4.2, "Charging requirements" . 4
9 7 Modification to 4.4.4, "Charge retention (self-discharge)" . 6
10 8 Modification to 4.4.5, “Requirements for battery capacity sizing" . 6
11 9 Modification to 4.6, "Fire protection" . 7
12 10 Modification to 4.9.2, "Battery information system" . 7
13 11 Modifications to the Bibliography . 8
14 European foreword
15 This document (prEN IEC 62973-2:2025/prAA:2026) has been prepared by CLC/SC 9XB “Electrical, electronic
16 and electromechanical material on board rolling stock, including associated software”.
17 This document is currently submitted to the Enquiry.
18 The following dates are proposed:
• latest date by which the existence of this (doa) dav + 6 months
document has 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 (dow) dav + 36 months
conflicting with this document have to be (to be confirmed or
withdrawn modified when voting)
19 1 Modification to Clause 2, “Normative references”
20 Replace the reference to IEC 60623:2017 in Clause 2 and throughout the text with the following:
21 IEC/FDIS 60623:2026, Secondary cells and batteries containing alkaline or other non-acid electrolytes -
22 Vented nickel-cadmium prismatic rechargeable cells and batteries for use in industrial applications
23 Replace the reference to IEC 62259:2003 in Clause 2 and throughout the text with the following:
24 IEC/FDIS 62259:2026, Secondary cells and batteries containing alkaline or other non-acid electrolytes - Nickel-
25 cadmium prismatic rechargeable cells with partial gas recombination and batteries for use in industrial
26 applications
27 2 Modification to 3.1, “Terms and definitions”
28 Add the following new term entry:
29 “
30 3.1.15
31 reference test current
32 charge or discharge current of a cell or battery, expressed in amperes, having the same numerical value as the
33 rated capacity of that cell or battery, expressed in ampere-hours
34 EXAMPLE For a battery rated at 5 Ah during an n-hour discharge, the reference test current I equals 5 A.
t
35 Note 1 to entry: As opposed to the rated current the reference test current is independent of the rate capability of the
36 battery.
37 [SOURCE: IEC 61434:1996]”
38 3 Modification to 3.2, “Abbreviated terms”
39 Add the following abbreviation:
“It reference test current (see 3.1.15)”
40 4 Modification to 4.2.5, “Pocket plate/electrode technology”
41 Add
...