oSIST prEN IEC 62973-3:2025/oprAA:2026
(Amendment)Railway applications - Rolling stock - Batteries for auxiliary power supply systems - Part 3: Lead acid batteries
General Information
- Abstract
The part 3 of IEC 62973 will get a European annex.
The European Annex will only contain additions regarding European operating conditions (such as temperature) and requirements (such as discharging/charging characteristic) as well as general additions (which are contained in EN 50547 but have not been adopted into the IEC).
- Status
- Not Published
- Public Enquiry End Date
- 30-Sep-2026
- Technical Committee
- ŽEN - Electrical applications for railways
- Current Stage
- 4020 - Public enquire (PE) (Adopted Project)
- Start Date
- 12-Aug-2026
- Due Date
- 30-Dec-2026
Overview
oSIST prEN IEC 62973-3:2025/oprAA:2026 is a European draft amendment to the international standard IEC 62973-3, specifically tailored for railway applications regarding lead acid batteries used in auxiliary power supply systems on rolling stock. This standard, under the organization CLC (CENELEC), supplements the main IEC document with additional requirements and clarifications relevant for European operating conditions, such as temperature variations, battery performance, fire protection, and transportation. It addresses the necessary modifications, harmonizes with relevant European directives, and consolidates industry best practices for the safe and efficient use of lead acid batteries in railway environments.
Key Topics
Lead Acid Battery Types
- Vented (liquid electrolyte, e.g., grid and tubular plate types)
- Valve-Regulated Lead Acid (VRLA) including GEL and AGM types
European Operating Conditions
- Additional requirements for temperature tolerances and discharging/charging characteristics
- Modified charging parameters and temperature compensation needs
Performance and Safety
- Charge retention (self-discharge) limits for different battery technologies
- Guidelines for battery sizing and capacity based on emergency scenarios and ambient conditions
- Mandatory reference to fire protection practices (EN 45545 series)
Testing and Compliance
- References updated shock and vibration testing methodologies (IEC 61373:2026)
- Additions to transport regulations aligning with ADR/RID provisions for dangerous goods
- Enhanced test requirements, including short-circuit, valve operation, and post-vibration performance
Battery Information Systems
- Clarifies limitations on energy calculation methods for lead acid batteries
- Recommends approaches for estimating state of charge (SOC) under operational conditions
Applications
The standard is vital for professionals involved in the design, manufacturing, integration, and maintenance of railway rolling stock auxiliary power systems. Key application areas include:
Design and Procurement
- Specifying battery systems for new or refurbished rolling stock
- Ensuring all battery components meet robust European and international safety and performance criteria
System Integration
- Matching battery types (vented/VRLA) to application-specific needs such as emergency power or climate-dependent operation
Operations and Maintenance
- Applying the standard’s parameters for battery charging/discharging, fire protection, and capacity monitoring to extend product lifespan and reliability
- Ensuring safe, compliant transport, storage, and handling of lead acid batteries
Safety and Compliance
- Meeting the fire safety and shock/vibration resistance requirements essential for passenger and infrastructure protection
- Adhering to the latest legal requirements for hazardous material transportation
Related Standards
For interoperability and regulatory compliance, several related standards should be referenced alongside oSIST prEN IEC 62973-3:2025/oprAA:2026:
- EN 50547: General additional European battery requirements previously not integrated into IEC
- EN 50125-1: Environmental conditions for railway rolling stock equipment
- EN 50155: Electronic equipment for rolling stock
- EN 45545 series: Comprehensive fire protection requirements for railway vehicles
- IEC 61373:2026: Rolling stock equipment - Shock and vibration tests
- IEC 60896 series: General requirements and test methods for stationary lead acid batteries
In summary, oSIST prEN IEC 62973-3:2025/oprAA:2026 ensures that lead acid batteries used in railway rolling stock auxiliary systems are robust, safe, and optimized for challenging European operational environments. Adhering to this standard benefits manufacturers, operators, and integrators by delivering systems that are reliable, compliant, and tailored to the needs of modern rail networks.
Relations
- Effective Date
- 25-Feb-2025
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Frequently Asked Questions
oSIST prEN IEC 62973-3:2025/oprAA:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Railway applications - Rolling stock - Batteries for auxiliary power supply systems - Part 3: Lead acid batteries". This standard covers: The part 3 of IEC 62973 will get a European annex. The European Annex will only contain additions regarding European operating conditions (such as temperature) and requirements (such as discharging/charging characteristic) as well as general additions (which are contained in EN 50547 but have not been adopted into the IEC).
The part 3 of IEC 62973 will get a European annex. The European Annex will only contain additions regarding European operating conditions (such as temperature) and requirements (such as discharging/charging characteristic) as well as general additions (which are contained in EN 50547 but have not been adopted into the IEC).
oSIST prEN IEC 62973-3:2025/oprAA:2026 is classified under the following ICS (International Classification for Standards) categories: 29.220.20 - Acid secondary cells and batteries; 45.040 - Materials and components for railway engineering; 45.060.01 - Railway rolling stock in general. The ICS classification helps identify the subject area and facilitates finding related standards.
oSIST prEN IEC 62973-3:2025/oprAA:2026 has the following relationships with other standards: It is inter standard links to oSIST prEN IEC 62973-3:2025. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
oSIST prEN IEC 62973-3:2025/oprAA: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 - 3.
del: Svinčeve kislinske baterije - Dopolnilo AA
Railway applications - Rolling stock - Batteries for auxiliary power supply systems - Part
3: Lead acid batteries
Bahnanwendungen - Fahrzeuge - Batterien für Bordnetzversorgungssysteme - Teil 3:
Bleibatterien
Applications ferroviaires - Matériel roulant - Batteries pour systèmes d'alimentation
auxiliaire - Partie 3: Batteries au plomb
Ta slovenski standard je istoveten z: prEN IEC 62973-3:2025/prAA:2026
ICS:
29.220.20 Kislinski sekundarni členi in Acid secondary cells and
baterije batteries
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
oSIST prEN IEC 62973- en
3:2025/oprAA:2026
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD DRAFT
prEN IEC 62973-3:2025
NORME EUROPÉENNE
EUROPÄISCHE NORM
prAA
August 2026
ICS 29.220.20; 45.040 -
English Version
Railway applications - Rolling stock - Batteries for auxiliary
power supply systems - Part 3: Lead acid batteries
Applications ferroviaires - Matériel roulant - Batteries pour Bahnanwendungen - Fahrzeuge - Batterien für
systèmes d'alimentation auxiliaire - Partie 3: Batteries au Bordnetzversorgungssysteme - Teil 3: Bleibatterien
plomb
This draft amendment prAA, if approved, will modify the European Standard prEN IEC 62973-3:2025; 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: 81135 Ref. No. prEN IEC 62973-3:2025/prAA:2026 E
1 Contents Page
2 European foreword . 3
3 1 Modification to Clause 2, “Normative references” . 4
4 2 Modification to 4.2.1, “General” . 4
5 3 Modification to 4.4.1, “System voltage” . 4
6 4 Modification to 4.4.2, “Charging requirements” . 4
7 5 Modification to 4.4.4, "Charge retention (self-discharge)” . 6
8 6 Modification to 4.4.5, “Requirements for battery capacity sizing" . 6
9 7 Modification to 4.6, "Fire protection” . 7
10 8 Modification to 5.2, "Battery information system” . 7
11 9 Modification to 9.1, "Transportation” . 8
12 10 Modification to 10.2.2, "Tests for cells and monoblocs”. 8
13 11 Modification to 10.2.5, "Shock and vibration test” . 8
14 12 Modifications to the Bibliography . 9
15 European foreword
16 This document (prEN IEC 62973-3:2025/prAA:2026) has been prepared by CLC/SC 9XB “Electrical, electronic
17 and electromechanical material on board rolling stock, including associated software”.
18 This document is currently submitted to the Enquiry.
19 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)
20 1 Modification to Clause 2, “Normative references”
21 Replace the reference to IEC 61373:2010 in Clause 2 and throughout the text with the following:
22 IEC/FDIS 61373:2026, Railway applications - Rolling stock equipment - Shock and vibration tests
23 2 Modification to 4.2.1, “General”
24 Add the following paragraphs:
25 “Below is an overview of the different types of lead-acid batteries that are commonly used in batteries for
26 auxiliary power supply systems.
27 Lead acid batteries
28 in general, called type A
29 Lead acid batteries with vented technology (liquid electrolyte)
30 called A.1 with the sub types
31 A.11 - grid plates (vented),
32 A.12 - tubular positive plates (vented)
33 Lead acid batteries with valve-regulated-lead technology (non-liquid respectively absorbed-liquid electrolyte)
34 called A.2 with the subtypes
35 A.21 GEL grid plates (valve-regulated),
36 A.22 GEL tubular positive plates (valve-regulated),
37 A.23 AGM grid plate (valve-regulated)
38 3 Modification to 4.4.1, “System voltage”
39 Delete the first, second and third paragraphs.
40 Add the following paragraph:
41 “See prEN IEC 62973-1:2025, Clause 3 for system voltage value.”
42 4 Modification to 4.4.2, “Charging requirements”
43 Delete the whole content, except Table 1.
44 Add the following:
45 “
46 Charge characteristics are to be selected in a way to ensure high state of charge under normal operating
47 conditions, and lowest possible water consumption (for vented systems).
As impacted by prEN IEC 62973-1:2025/prAA:2026.
48 Table 2 — Typical lead acid battery charge parameters
Lead acid technology Vented VRLA Remarks
Gel AGM
Charging with single level
Charging voltage 2,32 -2,38 V/cell 2,32 -2,38 V/cell 2,27 -2,32 See solid line at
Figure 1
at +20°C V/cell
–––––––––––
Temperature -0,004 V /°K -0,003 V /°K…-0,004 V /°K
correction
Maximum Charging Normally no current limit is needed for this charging
Current
(recommendation in case of current limitation 10 to 40 A per 100 Ah)
In case of additional boost level
Charging voltage
...