IEC 62973-3:2024

• Abstract:

  IEC 62973-3:2024 establishes the framework for the selection and operation of lead acid batteries of the VRLA type for auxiliary power supply systems on rolling stock of railways and complements IEC 62973-1, unless otherwise specified. This document provides guidance and links to standards for the required battery qualification tests procedures and safety measures to be implemented. In this document, the most appropriate clauses of these cited standards have been selected and adapted as needed to reflect the intended use of these batteries as auxiliary power sources on rolling stock of railways.; The battery-specific requirements for subcomponents of battery systems such as containers, charging controls, temperature probes, nameplates and similar are covered in this document as needed.; Charging systems are excluded from the scope of this document.

• Status: Published
• Publication Date: 09-Apr-2024
• ICS: 29.220.20 - Acid secondary cells and batteries
• ICS: 45.040 - Materials and components for railway engineering
• ICS: 45.060.01 - Railway rolling stock in general
• Technical Committee: TC 9 - Electrical equipment and systems for railways
• Drafting Committee: PT 62973-3 - TC 9/PT 62973-3
• Current Stage: PPUB - Publication issued
• Start Date: 10-Apr-2024
• Completion Date: 12-Apr-2024

Overview - IEC 62973-3:2024 (Lead acid batteries for rolling stock)

IEC 62973-3:2024 is the industry standard that defines the framework for selecting, qualifying and operating VRLA lead acid batteries used as auxiliary power supplies on railway rolling stock. It complements IEC 62973‑1 and adapts relevant clauses from existing battery and safety standards to the specific environmental, mechanical and electrical conditions encountered on trains. Charging systems themselves are excluded; the document focuses on battery cells/monoblocs, containers and related subcomponents.

Key topics and technical requirements

The standard provides prescriptive guidance and test references for safe, reliable battery use in rail applications, including:

• Battery types and definitions - VRLA (valve-regulated lead acid) cells, monoblocs, trays, crates and battery boxes.
• Environmental and mechanical requirements - operating temperature ranges, shock & vibration criteria, ventilation and installation orientations.
• System requirements - system voltage considerations, battery sizing inputs/outputs, and charge retention (self‑discharge) expectations.
• Charging and discharging performance - float/boost charge characteristics, temperature compensation, discharge profiles and compliance with energy demand/load profiles.
• Safety & protection - deep-discharge behavior, thermal considerations, fire protection and recommended safety measures.
• Subcomponent requirements - containers, charging controls, temperature probes, nameplates and marking/labeling rules.
• Electrical interface & markings - external connections, nameplate content and safety signs for battery boxes, trays and cells.
• Storage, transport and maintenance - handling instructions, storage conditions and routine maintenance guidance.
• Testing and qualification - type tests and routine tests including dielectric tests, load profile verification, shock & vibration, and electrical checks. Annexes provide test sequences, dielectric test parameters and a method to verify compliance with energy demand.

Practical applications and target users

IEC 62973-3:2024 is intended for professionals involved in design, procurement, installation, testing and operation of battery systems on railway vehicles:

• Rolling stock manufacturers and systems integrators specifying auxiliary power systems
• Battery manufacturers and test houses qualifying VRLA lead acid cells for rail use
• Railway operators and maintenance organizations defining lifecycle and safety procedures
• Certification bodies assessing compliance with railway electrical safety and performance requirements

Related standards and implementation notes

• Complements IEC 62973‑1 (general framework for railway battery systems).
• Selects and adapts clauses from established battery and safety standards (normative references listed in the document).
• Charging systems are explicitly excluded; refer to applicable charging-system standards when specifying chargers.

Keywords: IEC 62973-3:2024, railway batteries, VRLA lead acid batteries, rolling stock auxiliary power, battery qualification tests, battery sizing, railway battery safety.

IEC 62973-3 ®
Edition 1.0 2024-04
INTERNATIONAL
STANDARD
Railway applications – Rolling stock – Batteries for auxiliary power supply
systems –
Part 3: Lead acid batteries
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IEC 62973-3 ®
Edition 1.0 2024-04
INTERNATIONAL
STANDARD
Railway applications – Rolling stock – Batteries for auxiliary power supply

systems –
Part 3: Lead acid batteries
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.220.20; 45.040 ISBN 978-2-8322-8567-1

– 2 – IEC 62973-3:2024 © IEC 2024
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 9
4 General requirements . 9
4.1 Definitions of components of a battery system . 9
4.2 Description of lead acid battery types . 10
4.2.1 General . 10
4.2.2 Lead acid batteries with valve-regulated cell design and immobilized
electrolyte . 11
4.3 Environmental conditions . 11
4.4 System requirements . 12
4.4.1 System voltage . 12
4.4.2 Charging requirements . 13
4.4.3 Discharging performances . 16
4.4.4 Charge retention(self-discharge) . 17
4.4.5 Requirements for battery sizing . 17
4.5 Safety and protection requirements . 18
4.5.1 General . 18
4.5.2 Deep discharge of batteries . 18
4.5.3 Temperature compensation during charging . 19
4.6 Fire protection . 19
4.7 Maintenance . 19
4.8 Charging characteristics . 19
5 Optional components of a battery system . 20
5.1 General . 20
5.2 Battery information system . 20
5.3 Battery heater . 20
5.4 Thermostat or cut-off switch . 20
6 Mechanical design of battery system . 21
6.1 General . 21
6.2 Interface mechanism . 21
6.3 Shock and vibration . 21
6.4 Ventilation of battery box . 21
7 Electrical interface . 22
7.1 General . 22
7.2 External electrical connections interface . 22
8 Markings. 22
8.1 Safety signs . 22
8.1.1 Outside the box . 22
8.1.2 Tray, crate or other places inside the box . 22
8.1.3 Cells and monoblocs . 23
8.2 Nameplate . 23
8.2.1 Battery box . 23

8.2.2 Nameplates on tray, crate or other nameplates inside the box . 23
9 Storage and transportation conditions . 23
9.1 Transportation . 23
9.2 Storage . 23
10 Testing . 24
10.1 General . 24
10.2 Type test . 24
10.2.1 General . 24
10.2.2 Tests for cells and monoblocs. 24
10.2.3 Dielectric test . 25
10.2.4 Load profile test . 25
10.2.5 Shock and vibration test . 25
10.3 Routine test . 26
10.3.1 General . 26
10.3.2 Visual checks . 26
10.3.3 Dielectric test . 26
10.3.4 Cell and monobloc voltages . 26
Annex A (informative) Declaration of test unit equivalence . 27
Annex B (normative) Dielectric test . 28
Annex C (normative) Compliance of battery with energy demand of load profile(s) . 29
C.1 General . 29
C.2 Battery sizing . 29
C.3 Compliance with energy demand of load profile . 29
C.3.1 General . 29
C.3.2 Test facility . 29
C.3.3 Test batteries . 29
C.3.4 Test procedures . 30
C.3.5 Energy demand compliance . 30
C.3.6 Test report . 30
Bibliography . 31

Figure 1 – Definition of single cells, monobloc, crate, tray and battery box . 10
Figure 2 – Example of the evolution of the voltage of a VRLA cell when discharged
with multiples of the 5 h rated current versus percentage of the 5 h rated capacity . 12
Figure 3 – Examples of current and voltage evolution during charge . 13
Figure 4 – Temperature versus voltage response graph for float charge operation . 15
Figure 5 – Temperature versus voltage response graph for boost charge operation . 16
Figure 6 – Examples of horizontal installation of VRLA cells and monoblocs . 21
Figure 7 – Typical schematic view of an electrical interface of a battery system . 22

Table 1 – Requirements for battery system charge operations . 13
Table 2 – Typical lead acid battery charge parameters . 14
Table 3 – Voltage and temperature reference levels for float charge operation . 15
Table 4 – Voltage and temperature reference levels for boost charge operation . 16
Table 5 – Input parameters required for the sizing of the battery to be provided by the

system integrator or end user . 17

– 4 – IEC 62973-3:2024 © IEC 2024
Table 6 – Output parameters provided at the conclusion of the sizing of the battery to
be provided by the battery system manufacturer . 18
Table 7 – Type tests for cells and monoblocs . 25
Table B.1 – Sequence for dielectric test . 28
Table B.2 – Voltages for dielectric test . 28

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RAILWAY APPLICATIONS – ROLLING STOCK –
BATTERIES FOR AUXILIARY POWER SUPPLY SYSTEMS –

Part 3: Lead acid batteries
FOREWORD
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IEC 62973-3 has been prepared by IEC technical committee 9: Electrical equipment and
systems for railways. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
9/3041/FDIS 9/3066/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.

– 6 – IEC 62973-3:2024 © IEC 2024
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 62973 series, published under the general title Railway applications
– Rolling stock – Batteries for auxiliary power supply 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.
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RAILWAY APPLICATIONS – ROLLING STOCK –
BATTERIES FOR AUXILIARY POWER SUPPLY SYSTEMS –

Part 3: Lead acid batteries
1 Scope
This part of IEC 62973 establishes the framework for the electrical interfaces to the train, and
the sizing (e.g., capacity, cell number, to meet the requested load profile) and operation of lead
acid batteries of the VRLA type for auxiliary power supply systems on rolling stock of railways
and complements IEC 62973-1, unless otherwise specified.
This document provides guidance and links to standards for the required battery qualification
tests procedures and safety measures to be implemented.
The cited normative references for lead acid batteries provide multiple requirements and tests
applicable for their qualification.
In this document, the most appropriate clauses of these cited standards have been selected
and adapted as needed to reflect the intended use of these batteries as auxiliary power sources
on rolling stock of railways.
The battery-specific requirements for subcomponents of battery systems such as containers,
charging controls, temperature probes, nameplates and similar are covered in this document
as needed.
Charging systems are excluded from the scope of 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 60896-21:2004, Stationary lead-acid batteries – Part 21: Valve regulated types – Methods
of test
IEC 60896-22:2004, Stationary lead-acid batteries – Part 22: Valve regulated types –
Requirements
IEC 61373:2010, Railway applications – Rolling stock equipment – Shock and vibration tests
IEC TS 61430, Secondary cells and batteries – Test methods for checking the performance of
devices designed for reducing explosion hazards – Lead-acid starter batteries
IEC TR 61431:2020, Guidelines for the use of monitor systems for lead-acid traction batteries
IEC 62485-2:2010, Safety requirements for secondary batteries and battery installations –
Part 2: Stationary batteries
– 8 – IEC 62973-3:2024 © IEC 2024
IEC 62498-1:2010, Railway applications – Environmental conditions for equipment – Part 1:
Equipment on board rolling stock
IEC 62973-1:2018, Railway applications – Rolling stock– Batteries for auxiliary power supply
systems – Part 1: General requirements
ISO/IEC 17025, General requirements for the competence of testing and calibration
laboratories
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions in IEC 62973-1:2018, and the
following apply.
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
NOTE All typical battery related descriptions are defined in IEC 60050-482.
3.1.1
lead dioxide lead battery
lead acid battery
secondary battery with an aqueous electrolyte based on dilute sulphuric acid, a positive
electrode of lead dioxide and a negative electrode of lead
[SOURCE: IEC 60050-482:2004, 482-05-01, modified – Note has been deleted.]
3.1.2
battery information system
data collection system to provide optional additional information and guidance for battery
operation and maintenance
3.1.3
valve regulated lead acid battery
VRLA
secondary battery in which cells are closed but have a valve which allows the escape of gas if
the internal pressure exceeds a predetermined value
Note 1 to entry: The cell or battery cannot normally receive additions to the electrolyte.
[SOURCE: IEC 60050-482:2004, 482-05-15]
3.1.4
finite element analysis
FEA
numerical mathematical analysis method simulating the mechanical behaviour of an assembly
3.1.5
line replaceable unit
LRU
modular component of equipment designed to be replaced at an operating location whilst the
equipment remains in the operating environment

3.1.6
state of charge
SOC
level of charge in ampere hours of the battery relative to its rated
capacity in ampere hours and expressed in percentage points
Note 1 to entry: A term interrelated with SOC, is the term depth of discharge (DOD), i.e., the level of discharge in
ampere hours of the battery system when related to the same rated capacity in ampere hours and expressed in
percentage points and where, by convention, 0 % DOD equals to 100 % SOC and 100 % DOD equals to 0 % SOC.
Note 2 to entry: The real capacity of the battery may be different from the rated, i.e., declared capacity.
3.1.7
rated capacity
C
n
capacity value of a battery system determined under
specified conditions as per IEC 60896-21 and IEC 60896-22, and declared by the battery
manufacturer
3.1.8
battery system
battery
system that includes battery tray(s), battery crate(s), monobloc(s), electrical components and/or
equipment and associated electromechanical components and connections
3.2 Abbreviated terms
AC Alternating Current
AGM Absorbent Glass Mat
DC Direct Current
U Rated battery voltage
B
U Test voltage
T
4 General requirements
4.1 Definitions of components of a battery system
The main components of a lead acid battery and their interdependence are shown in Figure 1.

– 10 – IEC 62973-3:2024 © IEC 2024

Figure 1 – Definition of single cells, monobloc, crate, tray and battery box
Some batteries may not include all of the above components, e.g., single cells may be installed
in a tray without crates. The designation LRU denotes its status of a line replaceable unit.
4.2 Description of lead acid battery types
4.2.1 General
A lead acid battery consists of an assembly of single cells or multiple-cell monoblocs. Each cell
contains stacks of several positive and negative plates that are separated by a separator,
immersed in electrolyte and connected through plate straps to the positive and negative
terminals. These extend to the outside of the cell or monobloc housing and serve as
interconnection points.
In the fully charged state the active material of the negative plate consists of lead and the active
material of the positive plate consists of lead dioxide.
In a discharged state the active material in both the positive and negative plates contain variable
amounts of the discharge reaction product, i.e., lead sulphate (PbSO ).
The electrolyte is dilute sulphuric acid (typically 40 % in weight), the density or concentration
of which depends on the specific cell design and state of charge.
As the electrolyte participates in the electro-chemical reactions, its density and concentration
are reduced during discharge in proportion of the ampere hours discharged.
4.2.2 Lead acid batteries with valve-regulated cell design and immobilized electrolyte
In the valve-regulated cell design the electrolyte is immobilized with a gelling agent (fumed SiO )
or with an AGM. This induces voids in the volume occupied by the electrolyte facilitating fast
gas transport and oxygen recombination.
The following cell types are in use on rolling stock.
Cell type a) built with either grid-type negative and positive plates or with grid-type negative
plates and tubular-type positive plates. The electrolyte is present in the form of a stiff gel.
Cell type b) built with grid-type negative and positive plates and with a limited amount of
electrolyte immobilized in an AGM.
An oxygen recombination reaction is operative in such cells and monoblocs reducing gassing
and electrolyte water loss.
The cells do not allow or require electrolyte level maintenance and can be operated in vertical
and horizontal position.
4.3 Environmental conditions
The system integrator or end user shall specify the ambient air temperature range in which the
battery is to be operated so that the most appropriate cell and monobloc design can be provided
by the battery manufacturer.
IEC 62498-1:2010 lists in Table 2 the appropriate inside vehicle compartment temperature
ranges identified as class T1 to TX.
Lead acid batteries can operate with proper safeguards in the temperature range from −25 °C
to +55 °C.
Operation outside this range impair service performance and life.
High battery temperatures accelerate battery ageing.
Low battery temperatures reduce actual available battery capacity.
It is recommended that not only the temperature level itself but also the cumulated duration at
a given temperature level shall be taken into consideration when battery life is to be anticipated.
Further environmental conditions to be taken in consideration are:
– Humidity: according to IEC 62498-1:2010
– Shock and vibration: according to IEC 61373:2010
– Altitude: according to IEC 62498-1:2010
Deviations may be agreed between end user and/or system integrator and cell/battery
manufacturer.
– 12 – IEC 62973-3:2024 © IEC 2024
4.4 System requirements
4.4.1 System voltage
The low voltage supply network has to allow operation of the connected equipment within the
minimum and maximum limits of the voltage range according to Table 1 of IEC 62973-1:2018.
The operation of the battery as power source shall occur within the agreed voltage limits
resulting from the resolved requirements of the battery manufacturer, system integrator and end
user.
The voltage during discharge of the battery system varies with elapsed time and current levels.
The actual cell design, state of charge (SOC), ageing, and ambient temperature additionally
influence this voltage. A discharge is terminated when a defined minimum battery system
voltage is reached as per Table 1 of IEC 62973-1:2018, taking into consideration for example
the voltage drop in connection cables.
To avoid excessive withdraw of capacity from the battery system and prevent a deep discharge
or polarity reversal of one or more cells in the battery system, the lower voltage limit has to be
taken into consideration for the battery sizing.
The typical evolution of cell voltage during a discharge is shown in Figure 2 as function of the
discharge current expressed in multiples of the rated 5 h current or I .
Figure 2 – Example of the evolution of the voltage of a VRLA cell when discharged with
multiples of the 5 h rated current versus percentage of the 5 h rated capacity
The evolution of charge current and charge voltage, during a constant-current-constant-voltage
(IU or CCCV) charge of a lead acid battery is shown in Figure 3.

a) Example of charge current curve b) Example of charge voltage curve

Figure 3 – Examples of current and voltage evolution during charge
4.4.2 Charging requirements
The proper battery charging conditions are specified by the battery manufacturer and shall
follow Table 1. Table 2 provides some typical charging parameters to be considered for the
battery system.
Table 1 – Requirements for battery system charge operations
Activity Requirement
A regulated constant-current-constant-voltage charge with the
Float charge mode operation
capability of float voltage compensation according to the battery
system temperature shall be used
Boost charge mode operation (if
A regulated constant-current-constant-voltage charge with:
applicable)
a) the capability of boost voltage compensation according to the
battery temperature;
b) a boost charge activation trigger algorithm;
c) a boost charge duration limiter;
shall be used
Charge voltage control The actual float and boost voltage shall not deviate, in the constant
voltage phase, by more than 1 % from the set value
Battery voltage monitoring The voltage shall be measured with the voltage sensing leads placed
as close as possible to the positive and negative terminals of the
battery system
Charge current control The actual charge current shall not deviate, in the constant current
phase, by more than 1 % from the set value
Charge current ripple mitigation The AC ripple level of the charge current shall not exceed the values
recommended in IEC 62485-2:2010, Table 2
In no case shall the current ripple induce a discharge of the battery
Temperature compensation The temperature related correction factors of the float and boost
charge voltage shall be provided by the battery manufacturer and in
the format of Figure 4 and Figure 5 and Table 3 and Table 4
The correction factors shall be implemented in the charge control logic
Temperature monitoring The actual temperature of the cells and monoblocs shall be determined
with an appropriate sensor placed, with preference, directly on the
hottest cell or monobloc of the battery system
Data loss default action In case of a loss of battery voltage information, the charge of the
battery system shall be stopped
The above numerical values are of informative value only. Limit values are as indicated or as specified by the
agreement between the battery manufacturer, system integrator and end user.

– 14 – IEC 62973-3:2024 © IEC 2024
Table 2 – Typical lead acid battery charge parameters
Float charge conditions
Float voltage 2,15 V/cell to 2,30 V/cell at 25 °C for unlimited duration and corrected for battery
temperature
Temperature correction factor -0,003 V/K/cell to -0,005 V/K/cell
Boost charge conditions
Boost voltage 2,30 V/cell to 2,45 V/cell at 25 °C and corrected for battery temperature
Boost charge duration not to exceed 8 h
Temperature correction factor -0,003 V/K/cell to -0,005 V/K/cell
2 I maximum
Charging current
The above numerical values are of informative value only. The battery manufacturer specifies values applicable
to the battery in consideration.

The purpose of the temperature compensation of the float or boost voltage is to adjust the
amount of charge current flowing through the battery when the ambient temperature increases
or decreases.
This adjustment prevents not only battery overheating and excessive electrolyte water loss at
high temperatures, but also assures the achievement of faster full charge at low temperatures.
The cell or monobloc manufacturer shall provide the appropriate reference values for this
compensation at cell/monobloc level (slope).
The battery system manufacturer shall define the optimized number of cells/monoblocs to best
fit the voltage limits at train level as specified in Table 1 of IEC 62973-1:2018 as shown in
Figure 4 and Table 3, based on the actual battery system design .
Charging permanently with a voltage above or below the cell or monobloc manufacturer
specified limits cause accelerated ageing and a premature loss of capacity. A periodic charge
under boost charge conditions may be recommended by the battery manufacturer to assure an
equalisation of the individual cell voltages.
The battery system manufacturer shall also provide the value of the maximum battery
temperature above which all charge has to be terminated/inhibited.

Figure 4 – Temperature versus voltage response graph for float charge operation
Table 3 – Voltage and temperature reference levels for float charge operation
Reference U in T in °C of Slope of voltage compensation per K in 0,00X V/K deviation from
point V/cell the battery the 25 °C reference temperature
1 U T
1 1
2 U T (25 °C)
To be provided by the cell or monobloc manufacturer
2 2
3 U T
3 3
T and T are the result of set point (25 °C) and slope.
1 3
The temperature monitoring in Table 3 shall be according to Table 1.
A boost charge is carried out so as to speed up the full recharge of the battery or equalize
diverging cell capacities and voltages. As the boost voltage is significantly higher than the float
voltage, the danger of a resulting thermal runaway increases and a correction of the voltage as
function of battery temperature becomes even more imperative.
The cell or monobloc manufacturer shall provide the appropriate reference values for this
compensation at cell/monobloc level (slope).
The battery system manufacturer shall define the optimized number of cells/monoblocs to best
fit the voltage limits at train level as specified in Table 1 of IEC 62973-1:2018 as shown in
Figure 5 and Table 4, based on the actual battery design.
The battery manufacturer shall specify under which conditions a boost charge shall be initiated
and terminated.
– 16 – IEC 62973-3:2024 © IEC 2024

Figure 5 – Temperature versus voltage response graph for boost charge operation
Table 4 – Voltage and temperature reference levels for boost charge operation
Reference U in T in °C of Slope of voltage Conditions Minimum interval
point V/cell the battery compensation per K in specified for between two boost
0,00Y V/K deviation from initiating and charges as
the 25 °C reference terminating a boost specified in hours
temperature charge or events
4 U T
4 4
To be provided by To be provided by
To be provided by the cell
5 U T (25 °C)
the battery system the battery system
5 5
or monobloc manufacturer
manufacturer manufacturer
6 U T
6 6
T and T are the result of set point (25 °C) and slope.
4 6
The temperature monitoring in Table 4 shall be according to Table 1.
4.4.3 Discharging performances
4.4.3.1 General
The discharge requirement of the specified load profile(s) shall be met.
4.4.3.2 Load profile
The load profile reflects the actual current and/or power and/or resistive loads versus time
requirement of the auxiliary battery in rolling stock application. The load profile shall be
associated with an operating temperature range (maximum and minimum temperatures as
specified by the system integrator or end user, as per 4.4.5 of IEC 62973-1:2018) and system
voltage limits. Typical load profiles are shown in IEC 62973-1:2018 as examples only.
Such a load profile may incorporate requirements for extended discharge durations and low or
high temperature performance and others such as fulfillment level over service life.

The system integrator or end user shall provide these load profiles and associated conditions.
4.4.4 Charge retention(self-discharge)
Batteries lose capacity when stored in open circuit. This loss is quantified under normalized
conditions with the pertinent test clause in IEC 60896-21:2004.
The battery manufacturer shall provide guidance for the maximum possible duration of storage
in open circuit before a recharge, as specified for such a task, becomes necessary. The
influence of storage temperature shall be provided by the battery manufacturer.
4.4.5 Requirements for battery sizing
The selection of the battery, capable of meeting the energy demands as auxiliary power source
on rolling stock, i.e., its sizing shall be carried out by the battery system manufacturer.
The required parameters for sizing are listed in Table 5 and shall be provided by the system
integrator or end user.
Table 5 – Input parameters required for the sizing of the battery to be provided
by the system integrator or end user
Required parameters Information format
Load profile(s) Load expressed in A or W or Ω over time or combinations thereof
Relevant ambient air temperature range i.e., minimum and maximum battery
Ambient air temperature
system ambient temperature
Relevant voltage range according to the planned or present auxiliary power
supply system of the rolling stock
Operating voltage window
Possible voltage drops in connections and cables to and from the battery shall
not be overlooked
Required cycle capability Total number of discharges to be achieved with the most demanding load profile
Required service life in Service life in months based on required cycle capability and specified air
calendar months temperatures
Load expressed in A or W or Ω over time or combinations thereof
Extended discharge event
Number of events per year
Performance margins for future List of potential future performance level(s) amendments
loads
User-specific demands, Any additional information and specifications
conditions or constraints
All ancillary conditions shall be made available to the battery manufacturer as early and as
complete as possible, so as not to impair or delay the battery sizing activity.
At an appropriate stage of the battery sizing process, the battery manufacturer shall provide
feedback to the system integrator and/or end user on the actual sized battery by providing data
as per Table 6.
– 18 – IEC 62973-3:2024 © IEC 2024
Table 6 – Output parameters provided at the conclusion of the sizing
of the battery to be provided by the battery system manufacturer
Required parameters Information format
Voltage versus time curves or similar curves of the battery when a discharge
Load profile(s) with the load profile(s) is carried out at the upper and lower temperature limits of
the specified air temperature range
Confirmation of operability of the battery system within the minimum and
Ambient air temperature
maximum battery system ambient temperatures
Maximum and minimum voltage of the battery under the selected load profile and
operating temperature conditions
Float voltage value at 25 °C
Operating voltage window Temperature correction factor as per Table 3 and Figure 4
Boost voltage value at 25 °C
Temperature correction factor and operating conditions as per Table 4 and
Figure 5
Number of achievable discharges with a specified load profile when operated at
25 °C
Required cycle capability
Cycle capability derating when operated at the upper air temperature limit
Achievable service life in months when operated at 25 °C with a specified load
profile
Required service life in
calendar months
Service life derating when operated permanently at the upper air temperature
limit
Achievable extended discharge duration, in minutes at 25 °C, when the battery is
continued to be discharged, at the end of a regular load profile discharge, with
Extended discharge event
the specified power or current or resistive load of the specified extended-
duration load profile
Performance margins for Spare performance available under specified conditions
future loads
User-specific demands, Information as applicable
conditions or constraints
4.5 Safety and protection requirements
4.5.1 General
The battery crates, trays and boxes and connection hardware shall be stable against the action
of chemicals such as traces of battery electrolyte, hydraulic fluids, salt solutions and similar.
IEC 62498-1:2010 provides further guidance for the environmental conditions to be
encountered in railway applications.
The choice of the materials shall assure that no degradation of load-carrying or electrical
isolation properties occur.
See also 6.4 for ventilation of battery system box and vent plugs with flame barriers.
The proper qualification test shall be defined by mutual agreement between the battery
manufacturer, system integrator and/or end user.
4.5.2 Deep discharge of batteries
Lead acid batteries may experience deep discharge conditions in service on rolling stock when
an excessive amount of capacity is withdrawn or a specific low voltage is reached during a
discharge.
The battery manufacturer shall specify when a deep discharge occurred either in terms of:
a) of ampere-hours discharged in discharge events between two charges and referred t
...

IEC 62973-3 ®
Edition 1.0 2024-04
INTERNATIONAL
STANDARD
Railway applications - Rolling stock - Batteries for auxiliary power supply
systems -
Part 3: Lead acid batteries
ICS 29.220.20; 45.060.01 ISBN 978-2-8327-1422-5

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CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 9
4 General requirements . 9
4.1 Definitions of components of a battery system . 9
4.2 Description of lead acid battery types . 10
4.2.1 General . 10
4.2.2 Lead acid batteries with valve-regulated cell design and immobilized
electrolyte . 11
4.3 Environmental conditions . 11
4.4 System requirements . 12
4.4.1 System voltage . 12
4.4.2 Charging requirements . 13
4.4.3 Discharging performances . 16
4.4.4 Charge retention(self-discharge) . 17
4.4.5 Requirements for battery sizing . 17
4.5 Safety and protection requirements . 18
4.5.1 General . 18
4.5.2 Deep discharge of batteries . 18
4.5.3 Temperature compensation during charging . 19
4.6 Fire protection . 19
4.7 Maintenance . 19
4.8 Charging characteristics . 19
5 Optional components of a battery system . 20
5.1 General . 20
5.2 Battery information system . 20
5.3 Battery heater . 20
5.4 Thermostat or cut-off switch . 20
6 Mechanical design of battery system . 21
6.1 General . 21
6.2 Interface mechanism . 21
6.3 Shock and vibration . 21
6.4 Ventilation of battery box . 21
7 Electrical interface . 22
7.1 General . 22
7.2 External electrical connections interface . 22
8 Markings. 22
8.1 Safety signs . 22
8.1.1 Outside the box . 22
8.1.2 Tray, crate or other places inside the box . 22
8.1.3 Cells and monoblocs . 23
8.2 Nameplate . 23
8.2.1 Battery box . 23

8.2.2 Nameplates on tray, crate or other nameplates inside the box . 23
9 Storage and transportation conditions . 23
9.1 Transportation . 23
9.2 Storage . 23
10 Testing . 24
10.1 General . 24
10.2 Type test . 24
10.2.1 General . 24
10.2.2 Tests for cells and monoblocs. 24
10.2.3 Dielectric test . 25
10.2.4 Load profile test . 25
10.2.5 Shock and vibration test . 25
10.3 Routine test . 26
10.3.1 General . 26
10.3.2 Visual checks . 26
10.3.3 Dielectric test . 26
10.3.4 Cell and monobloc voltages . 26
Annex A (informative) Declaration of test unit equivalence . 27
Annex B (normative) Dielectric test . 28
Annex C (normative) Compliance of battery with energy demand of load profile(s) . 29
C.1 General . 29
C.2 Battery sizing . 29
C.3 Compliance with energy demand of load profile . 29
C.3.1 General . 29
C.3.2 Test facility . 29
C.3.3 Test batteries . 29
C.3.4 Test procedures . 30
C.3.5 Energy demand compliance . 30
C.3.6 Test report . 30
Bibliography . 31

Figure 1 – Definition of single cells, monobloc, crate, tray and battery box . 10
Figure 2 – Example of the evolution of the voltage of a VRLA cell when discharged
with multiples of the 5 h rated current versus percentage of the 5 h rated capacity . 12
Figure 3 – Examples of current and voltage evolution during charge . 13
Figure 4 – Temperature versus voltage response graph for float charge operation . 15
Figure 5 – Temperature versus voltage response graph for boost charge operation . 16
Figure 6 – Examples of horizontal installation of VRLA cells and monoblocs . 21
Figure 7 – Typical schematic view of an electrical interface of a battery system . 22

Table 1 – Requirements for battery system charge operations . 13
Table 2 – Typical lead acid battery charge parameters . 14
Table 3 – Voltage and temperature reference levels for float charge operation . 15
Table 4 – Voltage and temperature reference levels for boost charge operation . 16
Table 5 – Input parameters required for the sizing of the battery to be provided by the

system integrator or end user . 17

– 4 – IEC 62973-3:2024 © IEC 2024
Table 6 – Output parameters provided at the conclusion of the sizing of the battery to
be provided by the battery system manufacturer . 18
Table 7 – Type tests for cells and monoblocs . 25
Table B.1 – Sequence for dielectric test . 28
Table B.2 – Voltages for dielectric test . 28

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RAILWAY APPLICATIONS – ROLLING STOCK –
BATTERIES FOR AUXILIARY POWER SUPPLY SYSTEMS –

Part 3: Lead acid batteries
FOREWORD
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IEC 62973-3 has been prepared by IEC technical committee 9: Electrical equipment and
systems for railways. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
9/3041/FDIS 9/3066/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.

– 6 – IEC 62973-3:2024 © IEC 2024
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 62973 series, published under the general title Railway applications
– Rolling stock – Batteries for auxiliary power supply 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.
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.

RAILWAY APPLICATIONS – ROLLING STOCK –
BATTERIES FOR AUXILIARY POWER SUPPLY SYSTEMS –

Part 3: Lead acid batteries
1 Scope
This part of IEC 62973 establishes the framework for the electrical interfaces to the train, and
the sizing (e.g., capacity, cell number, to meet the requested load profile) and operation of lead
acid batteries of the VRLA type for auxiliary power supply systems on rolling stock of railways
and complements IEC 62973-1, unless otherwise specified.
This document provides guidance and links to standards for the required battery qualification
tests procedures and safety measures to be implemented.
The cited normative references for lead acid batteries provide multiple requirements and tests
applicable for their qualification.
In this document, the most appropriate clauses of these cited standards have been selected
and adapted as needed to reflect the intended use of these batteries as auxiliary power sources
on rolling stock of railways.
The battery-specific requirements for subcomponents of battery systems such as containers,
charging controls, temperature probes, nameplates and similar are covered in this document
as needed.
Charging systems are excluded from the scope of 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 60896-21:2004, Stationary lead-acid batteries – Part 21: Valve regulated types – Methods
of test
IEC 60896-22:2004, Stationary lead-acid batteries – Part 22: Valve regulated types –
Requirements
IEC 61373:2010, Railway applications – Rolling stock equipment – Shock and vibration tests
IEC TS 61430, Secondary cells and batteries – Test methods for checking the performance of
devices designed for reducing explosion hazards – Lead-acid starter batteries
IEC TR 61431:2020, Guidelines for the use of monitor systems for lead-acid traction batteries
IEC 62485-2:2010, Safety requirements for secondary batteries and battery installations –
Part 2: Stationary batteries
– 8 – IEC 62973-3:2024 © IEC 2024
IEC 62498-1:2010, Railway applications – Environmental conditions for equipment – Part 1:
Equipment on board rolling stock
IEC 62973-1:2018, Railway applications – Rolling stock– Batteries for auxiliary power supply
systems – Part 1: General requirements
ISO/IEC 17025, General requirements for the competence of testing and calibration
laboratories
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions in IEC 62973-1:2018, and the
following apply.
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
NOTE All typical battery related descriptions are defined in IEC 60050-482.
3.1.1
lead dioxide lead battery
lead acid battery
secondary battery with an aqueous electrolyte based on dilute sulphuric acid, a positive
electrode of lead dioxide and a negative electrode of lead
[SOURCE: IEC 60050-482:2004, 482-05-01, modified – Note has been deleted.]
3.1.2
battery information system
data collection system to provide optional additional information and guidance for battery
operation and maintenance
3.1.3
valve regulated lead acid battery
VRLA
secondary battery in which cells are closed but have a valve which allows the escape of gas if
the internal pressure exceeds a predetermined value
Note 1 to entry: The cell or battery cannot normally receive additions to the electrolyte.
[SOURCE: IEC 60050-482:2004, 482-05-15]
3.1.4
finite element analysis
FEA
numerical mathematical analysis method simulating the mechanical behaviour of an assembly
3.1.5
line replaceable unit
LRU
modular component of equipment designed to be replaced at an operating location whilst the
equipment remains in the operating environment

3.1.6
state of charge
SOC
level of charge in ampere hours of the battery relative to its rated
capacity in ampere hours and expressed in percentage points
Note 1 to entry: A term interrelated with SOC, is the term depth of discharge (DOD), i.e., the level of discharge in
ampere hours of the battery system when related to the same rated capacity in ampere hours and expressed in
percentage points and where, by convention, 0 % DOD equals to 100 % SOC and 100 % DOD equals to 0 % SOC.
Note 2 to entry: The real capacity of the battery may be different from the rated, i.e., declared capacity.
3.1.7
rated capacity
C
n
capacity value of a battery system determined under
specified conditions as per IEC 60896-21 and IEC 60896-22, and declared by the battery
manufacturer
3.1.8
battery system
battery
system that includes battery tray(s), battery crate(s), monobloc(s), electrical components and/or
equipment and associated electromechanical components and connections
3.2 Abbreviated terms
AC Alternating Current
AGM Absorbent Glass Mat
DC Direct Current
U Rated battery voltage
B
U Test voltage
T
4 General requirements
4.1 Definitions of components of a battery system
The main components of a lead acid battery and their interdependence are shown in Figure 1.

– 10 – IEC 62973-3:2024 © IEC 2024

Figure 1 – Definition of single cells, monobloc, crate, tray and battery box
Some batteries may not include all of the above components, e.g., single cells may be installed
in a tray without crates. The designation LRU denotes its status of a line replaceable unit.
4.2 Description of lead acid battery types
4.2.1 General
A lead acid battery consists of an assembly of single cells or multiple-cell monoblocs. Each cell
contains stacks of several positive and negative plates that are separated by a separator,
immersed in electrolyte and connected through plate straps to the positive and negative
terminals. These extend to the outside of the cell or monobloc housing and serve as
interconnection points.
In the fully charged state the active material of the negative plate consists of lead and the active
material of the positive plate consists of lead dioxide.
In a discharged state the active material in both the positive and negative plates contain variable
amounts of the discharge reaction product, i.e., lead sulphate (PbSO ).
The electrolyte is dilute sulphuric acid (typically 40 % in weight), the density or concentration
of which depends on the specific cell design and state of charge.
As the electrolyte participates in the electro-chemical reactions, its density and concentration
are reduced during discharge in proportion of the ampere hours discharged.
4.2.2 Lead acid batteries with valve-regulated cell design and immobilized electrolyte
In the valve-regulated cell design the electrolyte is immobilized with a gelling agent (fumed SiO )
or with an AGM. This induces voids in the volume occupied by the electrolyte facilitating fast
gas transport and oxygen recombination.
The following cell types are in use on rolling stock.
Cell type a) built with either grid-type negative and positive plates or with grid-type negative
plates and tubular-type positive plates. The electrolyte is present in the form of a stiff gel.
Cell type b) built with grid-type negative and positive plates and with a limited amount of
electrolyte immobilized in an AGM.
An oxygen recombination reaction is operative in such cells and monoblocs reducing gassing
and electrolyte water loss.
The cells do not allow or require electrolyte level maintenance and can be operated in vertical
and horizontal position.
4.3 Environmental conditions
The system integrator or end user shall specify the ambient air temperature range in which the
battery is to be operated so that the most appropriate cell and monobloc design can be provided
by the battery manufacturer.
IEC 62498-1:2010 lists in Table 2 the appropriate inside vehicle compartment temperature
ranges identified as class T1 to TX.
Lead acid batteries can operate with proper safeguards in the temperature range from −25 °C
to +55 °C.
Operation outside this range impair service performance and life.
High battery temperatures accelerate battery ageing.
Low battery temperatures reduce actual available battery capacity.
It is recommended that not only the temperature level itself but also the cumulated duration at
a given temperature level shall be taken into consideration when battery life is to be anticipated.
Further environmental conditions to be taken in consideration are:
– Humidity: according to IEC 62498-1:2010
– Shock and vibration: according to IEC 61373:2010
– Altitude: according to IEC 62498-1:2010
Deviations may be agreed between end user and/or system integrator and cell/battery
manufacturer.
– 12 – IEC 62973-3:2024 © IEC 2024
4.4 System requirements
4.4.1 System voltage
The low voltage supply network has to allow operation of the connected equipment within the
minimum and maximum limits of the voltage range according to Table 1 of IEC 62973-1:2018.
The operation of the battery as power source shall occur within the agreed voltage limits
resulting from the resolved requirements of the battery manufacturer, system integrator and end
user.
The voltage during discharge of the battery system varies with elapsed time and current levels.
The actual cell design, state of charge (SOC), ageing, and ambient temperature additionally
influence this voltage. A discharge is terminated when a defined minimum battery system
voltage is reached as per Table 1 of IEC 62973-1:2018, taking into consideration for example
the voltage drop in connection cables.
To avoid excessive withdraw of capacity from the battery system and prevent a deep discharge
or polarity reversal of one or more cells in the battery system, the lower voltage limit has to be
taken into consideration for the battery sizing.
The typical evolution of cell voltage during a discharge is shown in Figure 2 as function of the
discharge current expressed in multiples of the rated 5 h current or I .
Figure 2 – Example of the evolution of the voltage of a VRLA cell when discharged with
multiples of the 5 h rated current versus percentage of the 5 h rated capacity
The evolution of charge current and charge voltage, during a constant-current-constant-voltage
(IU or CCCV) charge of a lead acid battery is shown in Figure 3.

a) Example of charge current curve b) Example of charge voltage curve

Figure 3 – Examples of current and voltage evolution during charge
4.4.2 Charging requirements
The proper battery charging conditions are specified by the battery manufacturer and shall
follow Table 1. Table 2 provides some typical charging parameters to be considered for the
battery system.
Table 1 – Requirements for battery system charge operations
Activity Requirement
A regulated constant-current-constant-voltage charge with the
Float charge mode operation
capability of float voltage compensation according to the battery
system temperature shall be used
Boost charge mode operation (if
A regulated constant-current-constant-voltage charge with:
applicable)
a) the capability of boost voltage compensation according to the
battery temperature;
b) a boost charge activation trigger algorithm;
c) a boost charge duration limiter;
shall be used
Charge voltage control The actual float and boost voltage shall not deviate, in the constant
voltage phase, by more than 1 % from the set value
Battery voltage monitoring The voltage shall be measured with the voltage sensing leads placed
as close as possible to the positive and negative terminals of the
battery system
Charge current control The actual charge current shall not deviate, in the constant current
phase, by more than 1 % from the set value
Charge current ripple mitigation The AC ripple level of the charge current shall not exceed the values
recommended in IEC 62485-2:2010, Table 2
In no case shall the current ripple induce a discharge of the battery
Temperature compensation The temperature related correction factors of the float and boost
charge voltage shall be provided by the battery manufacturer and in
the format of Figure 4 and Figure 5 and Table 3 and Table 4
The correction factors shall be implemented in the charge control logic
Temperature monitoring The actual temperature of the cells and monoblocs shall be determined
with an appropriate sensor placed, with preference, directly on the
hottest cell or monobloc of the battery system
Data loss default action In case of a loss of battery voltage information, the charge of the
battery system shall be stopped
The above numerical values are of informative value only. Limit values are as indicated or as specified by the
agreement between the battery manufacturer, system integrator and end user.

– 14 – IEC 62973-3:2024 © IEC 2024
Table 2 – Typical lead acid battery charge parameters
Float charge conditions
Float voltage 2,15 V/cell to 2,30 V/cell at 25 °C for unlimited duration and corrected for battery
temperature
Temperature correction factor -0,003 V/K/cell to -0,005 V/K/cell
Boost charge conditions
Boost voltage 2,30 V/cell to 2,45 V/cell at 25 °C and corrected for battery temperature
Boost charge duration not to exceed 8 h
Temperature correction factor -0,003 V/K/cell to -0,005 V/K/cell
2 I maximum
Charging current
The above numerical values are of informative value only. The battery manufacturer specifies values applicable
to the battery in consideration.

The purpose of the temperature compensation of the float or boost voltage is to adjust the
amount of charge current flowing through the battery when the ambient temperature increases
or decreases.
This adjustment prevents not only battery overheating and excessive electrolyte water loss at
high temperatures, but also assures the achievement of faster full charge at low temperatures.
The cell or monobloc manufacturer shall provide the appropriate reference values for this
compensation at cell/monobloc level (slope).
The battery system manufacturer shall define the optimized number of cells/monoblocs to best
fit the voltage limits at train level as specified in Table 1 of IEC 62973-1:2018 as shown in
Figure 4 and Table 3, based on the actual battery system design .
Charging permanently with a voltage above or below the cell or monobloc manufacturer
specified limits cause accelerated ageing and a premature loss of capacity. A periodic charge
under boost charge conditions may be recommended by the battery manufacturer to assure an
equalisation of the individual cell voltages.
The battery system manufacturer shall also provide the value of the maximum battery
temperature above which all charge has to be terminated/inhibited.

Figure 4 – Temperature versus voltage response graph for float charge operation
Table 3 – Voltage and temperature reference levels for float charge operation
Reference U in T in °C of Slope of voltage compensation per K in 0,00X V/K deviation from
point V/cell the battery the 25 °C reference temperature
1 U T
1 1
2 U T (25 °C)
To be provided by the cell or monobloc manufacturer
2 2
3 U T
3 3
T and T are the result of set point (25 °C) and slope.
1 3
The temperature monitoring in Table 3 shall be according to Table 1.
A boost charge is carried out so as to speed up the full recharge of the battery or equalize
diverging cell capacities and voltages. As the boost voltage is significantly higher than the float
voltage, the danger of a resulting thermal runaway increases and a correction of the voltage as
function of battery temperature becomes even more imperative.
The cell or monobloc manufacturer shall provide the appropriate reference values for this
compensation at cell/monobloc level (slope).
The battery system manufacturer shall define the optimized number of cells/monoblocs to best
fit the voltage limits at train level as specified in Table 1 of IEC 62973-1:2018 as shown in
Figure 5 and Table 4, based on the actual battery design.
The battery manufacturer shall specify under which conditions a boost charge shall be initiated
and terminated.
– 16 – IEC 62973-3:2024 © IEC 2024

Figure 5 – Temperature versus voltage response graph for boost charge operation
Table 4 – Voltage and temperature reference levels for boost charge operation
Reference U in T in °C of Slope of voltage Conditions Minimum interval
point V/cell the battery compensation per K in specified for between two boost
0,00Y V/K deviation from initiating and charges as
the 25 °C reference terminating a boost specified in hours
temperature charge or events
4 U T
4 4
To be provided by To be provided by
To be provided by the cell
5 U T (25 °C)
the battery system the battery system
5 5
or monobloc manufacturer
manufacturer manufacturer
6 U T
6 6
T and T are the result of set point (25 °C) and slope.
4 6
The temperature monitoring in Table 4 shall be according to Table 1.
4.4.3 Discharging performances
4.4.3.1 General
The discharge requirement of the specified load profile(s) shall be met.
4.4.3.2 Load profile
The load profile reflects the actual current and/or power and/or resistive loads versus time
requirement of the auxiliary battery in rolling stock application. The load profile shall be
associated with an operating temperature range (maximum and minimum temperatures as
specified by the system integrator or end user, as per 4.4.5 of IEC 62973-1:2018) and system
voltage limits. Typical load profiles are shown in IEC 62973-1:2018 as examples only.
Such a load profile may incorporate requirements for extended discharge durations and low or
high temperature performance and others such as fulfillment level over service life.

The system integrator or end user shall provide these load profiles and associated conditions.
4.4.4 Charge retention(self-discharge)
Batteries lose capacity when stored in open circuit. This loss is quantified under normalized
conditions with the pertinent test clause in IEC 60896-21:2004.
The battery manufacturer shall provide guidance for the maximum possible duration of storage
in open circuit before a recharge, as specified for such a task, becomes necessary. The
influence of storage temperature shall be provided by the battery manufacturer.
4.4.5 Requirements for battery sizing
The selection of the battery, capable of meeting the energy demands as auxiliary power source
on rolling stock, i.e., its sizing shall be carried out by the battery system manufacturer.
The required parameters for sizing are listed in Table 5 and shall be provided by the system
integrator or end user.
Table 5 – Input parameters required for the sizing of the battery to be provided
by the system integrator or end user
Required parameters Information format
Load profile(s) Load expressed in A or W or Ω over time or combinations thereof
Relevant ambient air temperature range i.e., minimum and maximum battery
Ambient air temperature
system ambient temperature
Relevant voltage range according to the planned or present auxiliary power
supply system of the rolling stock
Operating voltage window
Possible voltage drops in connections and cables to and from the battery shall
not be overlooked
Required cycle capability Total number of discharges to be achieved with the most demanding load profile
Required service life in Service life in months based on required cycle capability and specified air
calendar months temperatures
Load expressed in A or W or Ω over time or combinations thereof
Extended discharge event
Number of events per year
Performance margins for future List of potential future performance level(s) amendments
loads
User-specific demands, Any additional information and specifications
conditions or constraints
All ancillary conditions shall be made available to the battery manufacturer as early and as
complete as possible, so as not to impair or delay the battery sizing activity.
At an appropriate stage of the battery sizing process, the battery manufacturer shall provide
feedback to the system integrator and/or end user on the actual sized battery by providing data
as per Table 6.
– 18 – IEC 62973-3:2024 © IEC 2024
Table 6 – Output parameters provided at the conclusion of the sizing
of the battery to be provided by the battery system manufacturer
Required parameters Information format
Voltage versus time curves or similar curves of the battery when a discharge
Load profile(s) with the load profile(s) is carried out at the upper and lower temperature limits of
the specified air temperature range
Confirmation of operability of the battery system within the minimum and
Ambient air temperature
maximum battery system ambient temperatures
Maximum and minimum voltage of the battery under the selected load profile and
operating temperature conditions
Float voltage value at 25 °C
Operating voltage window Temperature correction factor as per Table 3 and Figure 4
Boost voltage value at 25 °C
Temperature correction factor and operating conditions as per Table 4 and
Figure 5
Number of achievable discharges with a specified load profile when operated at
25 °C
Required cycle capability
Cycle capability derating when operated at the upper air temperature limit
Achievable service life in months when operated at 25 °C with a specified load
profile
Required service life in
calendar months
Service life derating when operated permanently at the upper air temperature
limit
Achievable extended discharge duration, in minutes at 25 °C, when the battery is
continued to be discharged, at the end of a regular load profile discharge, with
Extended discharge event
the specified power or current or resistive load of the specified extended-
duration load profile
Performance margins for Spare performance available under specified conditions
future loads
User-specific demands, Information as applicable
conditions or constraints
4.5 Safety and protection requirements
4.5.1 General
The battery crates, trays and boxes and connection hardware shall be stable against the action
of chemicals such as traces of battery electrolyte, hydraulic fluids, salt solutions and similar.
IEC 62498-1:2010 provides further guidance for the environmental conditions to be
encountered in railway applications.
The choice of the materials shall assure that no degradation of load-carrying or electrical
isolation properties occur.
See also 6.4 for ventilation of battery system box and vent plugs with flame barriers.
The proper qualification test shall be defined by mutual agreement between the battery
manufacturer, system integrator and/or end user.
4.5.2 Deep discharge of batteries
Lead acid batteries may experience deep discharge conditions in service on rolling stock when
an excessive amount of capacity is withdrawn or a specific low voltage is reached during a
discharge.
The battery manufacturer shall specify when a deep discharge occurred either in terms of:
a) of ampere-hours discharged in discharge events between two charges and referred to the
rated capacity;
b) when the voltage on discharge falls below a defined limit for a significant period of time.
The battery manufacturer shall specify the proper charging conditions and eventual additional
maintenance operations required to counteract and mitigate negative effects of such deep
discharges.
The battery manufacturer shall also, if feasible, adapt the cell design in such a way that a
permanent damage due to deep discharges can be prevented.
An extended discharge is
...

IEC 62973-3 ®
Edition 1.0 2024-04
NORME
INTERNATIONALE
Applications ferroviaires - Matériel roulant - Batteries pour systèmes
d'alimentation auxiliaires -
Partie 3 : Batteries au plomb
ICS 29.220.20; 45.060.01 ISBN 978-2-8327-1422-5

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– 32 – IEC 62973-3:2024 © IEC 2024
SOMMAIRE
AVANT-PROPOS . 35
1 Domaine d'application . 37
2 Références normatives . 37
3 Termes, définitions et termes abrégés . 38
3.1 Termes et définitions . 38
3.2 Termes abrégés . 39
4 Exigences générales . 40
4.1 Définitions des composants d'un système de batterie . 40
4.2 Description des types de batteries au plomb . 41
4.2.1 Généralités . 41
4.2.2 Batteries au plomb étanches à soupape et électrolyte immobilisé . 41
4.3 Conditions de températures ambiantes . 41
4.4 Exigences système . 42
4.4.1 Tension réseau . 42
4.4.2 Exigences de charge . 43
4.4.3 Performances de décharge . 47
4.4.4 Conservation de la charge (autodécharge) . 47
4.4.5 Exigences de dimensionnement de la batterie . 47
4.5 Exigences de sécurité et de protection . 49
4.5.1 Généralités . 49
4.5.2 Décharge profonde des batteries . 49
4.5.3 Compensation en température pendant la charge . 50
4.6 Protection contre les incendies . 50
4.7 Maintenance . 51
4.8 Caractéristiques de charge . 51
5 Composants facultatifs d'un système de batterie . 51
5.1 Généralités . 51
5.2 Système d'informations de la batterie. 51
5.3 Dispositif de chauffage de la batterie . 51
5.4 Thermostat ou dispositif de coupure . 51
6 Conception mécanique du système de batterie . 52
6.1 Généralités . 52
6.2 Mécanisme d'interface . 52
6.3 Chocs et vibrations . 52
6.4 Ventilation du coffre batterie . 52
7 Interface électrique . 53
7.1 Généralités . 53
7.2 Interface des connexions électriques externes . 53
8 Marquages . 54
8.1 Symboles de sécurité . 54
8.1.1 Extérieur du coffre . 54
8.1.2 Caisse de groupement, châssis ou autres emplacements à l'intérieur du
coffre . 54
8.1.3 Éléments et monoblocs . 54
8.2 Plaque signalétique . 54
8.2.1 Coffre batterie . 54

8.2.2 Plaques signalétiques de la caisse de groupement, du châssis ou
autres plaques signalétiques à l'intérieur du coffre. 54
9 Conditions de stockage et de transport . 54
9.1 Transport . 54
9.2 Stockage. 55
10 Essais . 55
10.1 Généralités . 55
10.2 Essai de type . 55
10.2.1 Généralités . 55
10.2.2 Essais applicables aux éléments et monoblocs . 55
10.2.3 Essai diélectrique . 56
10.2.4 Essai de profil de charge . 56
10.2.5 Essai de chocs et vibrations . 56
10.3 Essai individuel de série . 57
10.3.1 Généralités . 57
10.3.2 Vérifications visuelles . 57
10.3.3 Essai diélectrique . 57
10.3.4 Tensions des éléments et monoblocs . 57
Annexe A (informative) Déclaration d'équivalence des unités soumises à l'essai . 58
Annexe B (normative)  Essai diélectrique . 59
Annexe C (normative) Conformité de la batterie aux besoins énergétiques du ou des

profil(s) de charge . 60
C.1 Généralités . 60
C.2 Dimensionnement de la batterie . 60
C.3 Conformité aux besoins énergétiques du profil de charge . 60
C.3.1 Généralités . 60
C.3.2 Installation d'essai . 60
C.3.3 Essai des batteries . 60
C.3.4 Procédures d'essai . 61
C.3.5 Conformité à la demande énergétique . 61
C.3.6 Rapport d'essai . 62
Bibliographie . 63

Figure 1 – Représentation d'éléments individuels, d'un monobloc, d'un châssis, d'une
caisse de groupement et d'un coffre batterie . 40
Figure 2 – Exemple d'évolution de la tension d'un élément de batterie étanche à
soupapes lorsqu'il est déchargé par des multiples du courant assigné sur 5 heures par

rapport au pourcentage de la capacité assignée sur 5 heures . 43
Figure 3 – Exemples de l'évolution du courant et de la tension au cours d'une charge . 43
Figure 4 – Rapport graphique température/tension en charge flottante . 45
Figure 5 – Rapport graphique température/tension en charge rapide . 46
Figure 6 – Exemples d'installation horizontale d'éléments et monoblocs VRLA . 52
Figure 7 – Vue schématique type de l'interface électrique d'un système de batterie . 53

Tableau 1 – Exigences relatives aux opérations de charge du système de batterie . 44
Tableau 2 – Paramètres types de charge d'une batterie au plomb. 44
Tableau 3 – Niveaux de référence de tension et de température en charge flottante . 46
Tableau 4 – Niveaux de référence de tension et de température en charge rapide . 47

– 34 – IEC 62973-3:2024 © IEC 2024
Tableau 5 – Paramètres d'entrée requis pour le dimensionnement de la batterie à
fournir par l'intégrateur système ou l'utilisateur final . 48
Tableau 6 – Paramètres de sortie fournis à l'issue du dimensionnement de la batterie à

spécifier par le fabricant du système de batterie . 49
Tableau 7 – Essais de type applicables aux éléments et monoblocs . 56
Tableau B.1 – Séquence de l'essai diélectrique . 59
Tableau B.2 – Tensions de l'essai diélectrique . 59

COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
APPLICATIONS FERROVIAIRES – MATÉRIEL ROULANT –
BATTERIES POUR SYSTÈMES D'ALIMENTATION AUXILIAIRES –

Partie 3 : Batteries au plomb
AVANT-PROPOS
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référencées est obligatoire pour une application correcte de la présente publication.
9) L'IEC attire l'attention sur le fait que la mise en application du présent document peut entraîner l'utilisation d'un
ou de plusieurs brevets. L'IEC ne prend pas position quant à la preuve, à la validité et à l'applicabilité de tout
droit de brevet revendiqué à cet égard. À la date de publication du présent document, l'IEC n'avait pas reçu
notification qu'un ou plusieurs brevets pouvaient être nécessaires à sa mise en application. Toutefois, il y a lieu
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L'IEC ne saurait être tenue pour responsable de ne pas avoir identifié de tels droits de brevets et de ne pas avoir
signalé leur existence.
L'IEC 62973-3 a été établi par le comité d'études 9 de l'IEC : Matériels et systèmes électriques
ferroviaires. Il s'agit d'une Norme internationale.
La présente version bilingue (2026-08) correspond à la version anglaise monolingue publiée en
2024-04.
La version française de cette norme n'a pas été soumise au vote.
La langue utilisée lors du développement de la présente Norme internationale est l'anglais.

– 36 – IEC 62973-3:2024 © IEC 2024
Ce document a été rédigé selon les Directives ISO/IEC, Partie 2, il a été développé selon les
Directives ISO/IEC, Partie 1 et les Directives ISO/IEC, Supplément IEC, disponibles sous
www.iec.ch/members_experts/refdocs. Les principaux types de documents développés par
l'IEC sont décrits plus en détail à l'adresse www.iec.ch/standardsdev/publications.
Une liste de toutes les parties de la série IEC 62973, publiées sous le titre général Applications
ferroviaires – Matériel roulant – Batteries pour systèmes d'alimentation auxiliaire, peut être
consultée sur le site web de l'IEC.
Le comité a décidé que le contenu de ce document ne sera pas modifié avant la date de stabilité
indiquée sur le site web de l'IEC sous webstore.iec.ch dans les données relatives au document
recherché. À cette date, le document sera
• reconduit,
• supprimé, ou
• révisé.
IMPORTANT – Le logo "colour inside" qui se trouve sur la page de couverture de ce
document indique qu'il contient des couleurs qui sont considérées comme utiles à une
bonne compréhension de son contenu. Les utilisateurs devraient, par conséquent,
imprimer cette publication en utilisant une imprimante couleur.

APPLICATIONS FERROVIAIRES – MATÉRIEL ROULANT –
BATTERIES POUR SYSTÈMES D'ALIMENTATION AUXILIAIRES –

Partie 3 : Batteries au plomb
1 Domaine d'application
La présente partie de l'IEC 62973 établit le cadre régissant les interfaces électriques avec le
train, ainsi que le dimensionnement (par exemple, la capacité ou le numéro d'élément, afin de
satisfaire au profil de charge demandé) et l'exploitation des batteries au plomb de type VRLA
au sein de systèmes d'alimentation auxiliaire équipant du matériel roulant ferroviaire et, sauf
spécification contraire, complète l'IEC 62973-1.
Le présent document fournit des préconisations ainsi que des liens vers des normes en ce qui
concerne les procédures d'essais de qualification des batteries et les mesures de sécurité à
mettre en œuvre.
Les références normatives citées relativement aux batteries au plomb spécifient les différentes
exigences et les différents essais applicables à leur qualification.
Dans le présent document, les articles les plus appropriés des normes citées ont été choisis et
adaptés afin qu'ils reflètent l'utilisation prévue de ces batteries en tant que source d'énergie
auxiliaire sur du matériel roulant ferroviaire.
Les exigences spécifiques aux sous-composants de systèmes de batterie tels que les
conteneurs, les régulateurs de charge, les sondes de température, les plaques signalétiques et
autres sont couvertes par le présent document le cas échéant.
Les systèmes de charge ne relèvent pas du domaine d'application du présent document.
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu'ils constituent, pour tout ou partie
de leur contenu, des exigences du présent document. Pour les références datées, seule
l'édition citée s'applique. Pour les références non datées, la dernière édition du document de
référence s'applique (y compris les éventuels amendements).
IEC 60896-21:2004, Batteries stationnaires au plomb – Partie 21 : Types étanches à soupapes
– Méthodes d'essai
IEC 60896-22:2004, Batteries stationnaires au plomb – Partie 22 : VTypes étanches à
soupapes – Exigences
IEC 61373:2010, Applications ferroviaires – Matériel roulant – Essais de chocs et vibrations
IEC TS 61430, Accumulateurs – Méthodes d'essai pour la vérification de la performance des
dispositifs conçus pour réduire les risques d'explosion – Batteries de démarrage au plomb
IEC TR 61431:2020, Guidelines for the use of monitor systems for lead-acid traction batteries
(disponible en anglais seulement)

– 38 – IEC 62973-3:2024 © IEC 2024
IEC 62485-2:2010, Exigences de sécurité pour les batteries d'accumulateurs et les installations
de batteries – Partie 2 : Batteries stationnaires
IEC 62498-1:2010, Applications ferroviaires – Conditions d'environnement pour le matériel –
Partie 1 : Équipement embarqué du matériel roulant
IEC 62973-1:2018, Applications ferroviaires – Matériel roulant – Batteries pour systèmes
d'alimentation auxiliaire – Partie 1 : Exigences générales
EN ISO/IEC 17025, Exigences générales concernant la compétence des laboratoires
d'étalonnages et d'essais
3 Termes, définitions et termes abrégés
3.1 Termes et définitions
Pour les besoins du présent document, les termes et définitions donnés dans l'IEC 62973-
1:2018 ainsi que les suivants s'appliquent.
L'ISO et l'IEC tiennent à jour des bases de données terminologiques destinées à être utilisées
en normalisation, consultables aux adresses suivantes :
• IEC Electropedia : disponible à l'adresse http://www.electropedia.org/
• ISO Online browsing platform : disponible à l'adresse http://www.iso.org/obp
NOTE Les descriptions spécifiques aux batteries sont fournies dans l'IEC 60050-482.
3.1.1
batterie au plomb-bioxyde de plomb
batterie au plomb
batterie d'accumulateurs comprenant un électrolyte aqueux à base d'acide sulfurique dilué, une
électrode positive en bioxyde de plomb et une électrode négative en plomb
[SOURCE: IEC 60050-482:2004, 482-05-01, modifiée – La note a été supprimée.]
3.1.2
système d'informations de la batterie
système de collecte de données qui fournit des informations supplémentaires optionnelles et
des préconisations concernant l'utilisation et la maintenance de la batterie
3.1.3
batterie étanche à soupapes
VRLA
batterie d'accumulateurs dans laquelle les éléments sont fermés mais munis d'une soupape qui
permet l'échappement des gaz lorsque la pression interne excède une valeur prédéterminée
Note 1 à l'article: L'élément ou la batterie ne peuvent normalement pas recevoir d'addition à leur électrolyte.
Note 2 à l'article: L'abréviation « VRLA » est dérivée du terme anglais développé correspondant «Valve Regulated
Lead Acid Battery».
[SOURCE : IEC 60050-482:2004, 482-05-15]

3.1.4
analyse par éléments finis
FEA
simulation d'un phénomène physique par le biais d'une technique mathématique numérique
Note 1 à l'article: L'abréviation « FEA » est dérivée du terme anglais développé correspondant « Finite Element
Analysis ».
3.1.5
unité remplaçable en ligne
LRU
composant modulaire d'un équipement, conçu pour être remplacé sur un site d'exploitation alors
que l'équipement reste dans son environnement d'exploitation
Note 1 à l'article: L'abréviation « LRU » est dérivée du terme anglais développé correspondant « Line Replaceable
Unit ».
3.1.6
état de charge
SOC
niveau de charge en ampère-heure d'une batterie, par rapport à sa
capacité assignée en ampère-heure et exprimé en points de pourcentage
Note 1 à l'article: Un terme lié au SOC est la profondeur de décharge (DOD), c'est-à-dire le niveau de décharge en
ampères-heures du système de batterie par rapport à la même capacité assignée en ampères-heures, exprimé en
points de pourcentage, où, par convention, 0 % DOD équivaut à 100 % SOC et 100 % DOD équivaut à 0 % SOC.
Note 2 à l'article: La capacité réelle de la batterie peut être différente de la capacité assignée, c'est-à-dire de la
capacité déclarée.
Note 3 à l'article: L'abréviation « SOC » est dérivée du terme anglais développé correspondant « State Of
Charge ».
3.1.7
capacité assignée
C
n
valeur de la capacité d'un système de batterie
déterminée dans des conditions spécifiées conformément à l'IEC 60896-21 et à l'IEC 60896-22
et déclarée par le fabricant de la batterie
3.1.8
système de batterie
batterie
système comportant une ou plusieurs caisses de groupement, châssis, batteries monoblocs,
ainsi que des composants électriques et/ou des équipements ainsi que leurs composants et
connexions électromécaniques associés
3.2 Termes abrégés
CA Courant alternatif
AGM (Absorbent Glass Mat) Tapis de verre absorbant
CC Courant continu
U Tension assignée de la batterie
B
U Tension d'essai
T
– 40 – IEC 62973-3:2024 © IEC 2024
4 Exigences générales
4.1 Définitions des composants d'un système de batterie
Les principaux composants d'une batterie au plomb ainsi que leurs interdépendances sont
illustrés à la Figure 1.
Figure 1 – Représentation d'éléments individuels, d'un monobloc, d'un châssis, d'une
caisse de groupement et d'un coffre batterie
Certaines batteries peuvent ne pas inclure la totalité des composants illustrés ci-dessus ; par
exemple, les éléments individuels peuvent être installés dans une caisse de groupement, sans
châssis. La désignation LRU indique qu'il s'agit d'une unité remplaçable en ligne.

4.2 Description des types de batteries au plomb
4.2.1 Généralités
Une batterie au plomb se compose d'un ensemble d'éléments individuels ou de monoblocs à
plusieurs éléments. Chaque élément contient des piles de plusieurs plaques positives et
négatives, qui sont séparées par un séparateur, immergées dans un électrolyte et connectées
via des barrettes aux bornes positives et négatives. Celles-ci se prolongent à l'extérieur de
l'enceinte de l'élément ou du monobloc et servent de points d'interconnexion.
À l'état de charge complète, la matière active de la plaque négative se compose de plomb et la
matière active de la plaque positive se compose de bioxyde de plomb.
À l'état déchargé, la matière active de la plaque négative et de la plaque positive se compose
de quantités variables du produit de réaction de décharge, par exemple du sulfate de plomb
(PbSO ).
L'électrolyte se compose d'acide sulfurique dilué (généralement 40 % de sa masse) dont la
densité ou la concentration dépend de la conception et de l'état de charge de l'élément
concerné.
À mesure que l'électrolyte participe aux réactions électro-chimiques, sa densité et sa
concentration diminuent lors de la décharge proportionnellement aux ampères-heures
déchargés.
4.2.2 Batteries au plomb étanches à soupape et électrolyte immobilisé
Dans une batterie étanche à soupape, l'électrolyte est immobilisé par le biais d'un agent
gélifiant (SiO fumé) ou d'un tapis de verre absorbant (AGM). Ceci provoque des vides dans le
volume occupé par l'électrolyte, qui facilitent le transport rapide du gaz et la recombinaison de
l'oxygène.
Les types d'éléments suivants sont utilisés à bord de matériel roulant.
Le type d'élément a) composé soit de plaques de type grille négatives et positives, soit de
plaques de type grille négatives et de plaques de type tubulaire positives. L'électrolyte est sous
la forme d'un gel épais.
Le type d'élément b) composé de plaques de type grille positives et négatives, ainsi que d'une
quantité limitée d'électrolyte immobilisé dans un AGM.
Une réaction de recombinaison d'oxygène se produit dans ce type d'élément et de monobloc,
ce qui réduit le dégagement gazeux et la perte de liquide d'électrolyte.
Les éléments ne permettent ou n'exigent aucune maintenance du niveau d'électrolyte, et ils
peuvent être exploités en position verticale ou horizontale.
4.3 Conditions de températures ambiantes
L'intégrateur système ou l'utilisateur final doivent spécifier la classe ou la plage de
températures ambiantes dans laquelle la batterie doit être exploitée, afin que le fabricant de la
batterie puisse concevoir l'élément ou le monobloc le plus approprié.
Le Tableau 2 de l'IEC 62498-1:2010 répertorie les plages de températures appropriées à
l'intérieur d'un compartiment du véhicule et les identifie des classes T1 à TX.
Si elles sont dotées des protections adaptées, les batteries au plomb peuvent fonctionner sur
une plage de températures comprises entre -25° C et +55° C.

– 42 – IEC 62973-3:2024 © IEC 2024
L'exploitation en dehors de cette plage détériore leurs performances et leur durée de vie en
service.
Des températures élevées au niveau de la batterie accélèrent son vieillissement.
Des températures basses au niveau de la batterie réduisent sa capacité réelle disponible.
Il est recommandé que non seulement la température elle-même, mais aussi la durée cumulée
de fonctionnement à une température donnée soient prises en compte lors du calcul de la durée
de vie de la batterie.
Les autres conditions d'environnement à prendre en compte sont les suivantes :
– Humidité: conformément à l'IEC 62498-1:2010
– Chocs et vibrations: conformément à l'IEC 61373:2010
– Altitude: conformément à l'IEC 62498-1:2010
Des écarts peuvent être fixés d'un commun accord entre l'utilisateur final et/ou l'intégrateur
système et le fabricant d'élément / de batterie.
4.4 Exigences système
4.4.1 Tension réseau
Le réseau d'alimentation basse tension doit permettre le fonctionnement des équipements
raccordés dans les limites minimale et maximale de la plage de tensions selon le Tableau 1 de
l'IEC 62973-1:2018.
Si elle sert de source d'énergie, la batterie doit être utilisée dans le respect des limites de
tension fixées par accord selon les exigences du fabricant de la batterie, de l'intégrateur
système et de l'utilisateur final.
La tension au cours de la décharge du système de batterie varie en fonction du temps écoulé
et des niveaux de courant. La conception réelle de l'élément, l'état de charge (SOC), le
vieillissement et la température ambiante influent également sur cette tension. Une décharge
prend fin lorsqu'une tension minimale définie du système de batterie est atteinte, conformément
au Tableau 1 de l'IEC 62973-1:2018, en tenant compte, par exemple, de la chute de tension
dans les câbles de raccordement.
Afin d'éviter un prélèvement excessif de capacité sur le système de batterie et de prévenir une
décharge profonde ou une inversion de polarité d'un ou plusieurs éléments du système de
batterie, la limite inférieure de tension doit être prise en compte lors du dimensionnement de la
batterie.
L'évolution type de la tension d'un élément lors d'une décharge est illustrée à la Figure 2 en
fonction du courant de décharge exprimé en multiples du courant assigné sur 5 heures (I ).
Figure 2 – Exemple d'évolution de la tension d'un élément de batterie étanche à
soupapes lorsqu'il est déchargé par des multiples du courant assigné sur 5 heures par
rapport au pourcentage de la capacité assignée sur 5 heures
L'évolution du courant de charge et de la tension de charge au cours de la charge à courant-
constant et tension-constante (IU ou CCCV) d'une batterie au plomb est illustrée à la Figure 3.

a) Exemple de courbe de courant de charge b) Exemple de courbe de tension de charge

Figure 3 – Exemples de l'évolution du courant et de la tension au cours d'une charge
4.4.2 Exigences de charge
Les conditions adaptées de charge de la batterie sont spécifiées par le fabricant de la batterie
et doivent respecter le Tableau 1. Le Tableau 2 spécifie des paramètres types de charge à
prendre en compte pour le système de batterie.

– 44 – IEC 62973-3:2024 © IEC 2024
Tableau 1 – Exigences relatives aux opérations de charge du système de batterie
Activité Exigence
Exploitation en mode charge flottante Une charge régulée à courant-constant et tension-constante capable
de compenser la tension de flottement en fonction de la température
du système de batterie doit être utilisée
Exploitation en mode charge rapide (le Une charge à courant-constant et tension-constante :
cas échéant)
a) capable de compenser la tension d'amplification en fonction de la
température de la batterie ;
b) utilisant un algorithme déclenchant la charge rapide ;
c) utilisant un limiteur de durée de charge rapide ;
doit être utilisée
Commande de tension de charge Lors de la phase à tension constante, les tensions réelles de
flottement et d'amplification ne doivent pas dévier de plus de 1 % de la
valeur définie
Surveillance de la tension de la batterie La tension doit être mesurée en plaçant les électrodes à capteur de
tension aussi près que possible des bornes positive et négative du
système de batterie
Commande du courant de charge Lors de la phase à courant constant, le courant de charge réel ne doit
pas dévier de plus de 1 % de la valeur définie
Atténuation de l'ondulation du courant La part en courant d'ondulation alternatif du courant de charge ne doit
de charge pas dépasser les valeurs recommandées dans le Tableau 2 de
l'IEC 62485-2:2010
En aucun cas le courant d'ondulation ne doit induire la décharge de la
batterie
Compensation en température Les facteurs de correction relatifs à la température des tensions de
charge flottante et de charge rapide doivent être fournis par le
fabricant de la batterie, suivant le modèle de la Figure 4, de la
Figure 5, du Tableau 3 et du Tableau 4.
Les facteurs de correction doivent être mis en œuvre selon la logique
de commande de charge
Surveillance de la température La température réelle des éléments et des monoblocs doit être
déterminée grâce à un capteur adapté placé, de préférence,
directement sur l'élément ou le monobloc du système de batterie
Action par défaut en cas de perte de En cas de perte d'informations sur la tension de la batterie, la charge
données du système de batterie doit être inhibée
Les valeurs numériques ci-dessus sont purement informatives. Les valeurs limites sont telles qu'indiquées ou
spécifiées dans l'accord convenu entre le fabricant de la batterie, l'intégrateur système et l'utilisateur final.

Tableau 2 – Paramètres types de charge d'une batterie au plomb
Conditions de charge flottante
Tension de flottement De 2,15 V/élément à 2,30 V/élément à 25 °C pour une durée illimitée et avec
compensation par rapport à la température de la batterie
Facteur de correction de la température : de -0,003 V/K/élément à -
0,005 V/K/élément
Conditions de charge rapide
Tension d'amplification De 2,30 V/élément à 2,45 V/élément à 25 °C et avec compensation par rapport à la
température de la batterie
La durée de charge rapide ne doit pas excéder 8 h
Facteur de correction de la température : de -0,003 V/K/élément à -
0,005 V/K/élément
Valeur maximale de 2 I
Courant de charge
Les valeurs numériques ci-dessus sont purement informatives. Le fabricant de la batterie spécifie des valeurs
applicables à la batterie à l'étude.

L'objectif de la compensation en température de la tension de flottement et d'amplification
consiste à ajuster la quantité de courant de charge parcourant la batterie lorsque la température
ambiante augmente ou diminue.
Cet ajustement évite non seulement la surchauffe de la batterie et la perte excessive de liquide
d'électrolyte à des températures élevées, mais assure également une charge complète plus
rapide à des températures basses.
Le fabricant de l'élément ou du monobloc doit fournir les valeurs de référence appropriées pour
ladite compensation au niveau des éléments/monoblocs (courbe).
Le fabricant du système de batterie doit déterminer le nombre optimal d'éléments/monoblocs
permettant de respecter au mieux les limites de tension au niveau du train comme cela est
spécifié dans le Tableau 1 de l'IEC 62973-1:2018, et comme cela est représenté dans la
Figure 4 et le Tableau 3, sur la base du système de batterie réel.
Le fait de charger en permanence l'élément ou le monobloc avec une tension supérieure ou
inférieure aux limites spécifiées par le fabricant de l'élément ou du monobloc entraîne un
vieillissement accéléré et une perte prématurée de capacité. Il peut être recommandé par le
fabricant de la batterie de charger régulièrement la batterie en conditions de charge rapide afin
d'assurer l'égalisation des tensions de chaque élément.
Le fabricant de la batterie doit également fournir la valeur maximale de température de la
batterie au-dessus de laquelle toute charge doit être interrompue/inhibée.

Figure 4 – Rapport graphique température/tension en charge flottante

– 46 – IEC 62973-3:2024 © IEC 2024
Tableau 3 – Niveaux de référence de tension et de température en charge flottante
Point de U en T de la Courbe de compensation de la tension par K en 0,00X V/K en cas
référence V/élémen batterie d'écart avec la température de référence de 25 °C
t en °C
1 U T
1 1
U
2 T (25 °C)
À fournir par le fabricant de l'élément ou du monobloc
3 U T
3 3
T et T sont le résultat du point de consigne (25 °C) et de la courbe.
1 3
La surveillance de la température indiquée au Tableau 3 doit être conforme au Tableau 1.
Une charge rapide consiste à accélérer la recharge complète d'une batterie ou à égaliser les
capacités et tensions divergentes des éléments. Étant donné que la tension d'amplification est
considérablement supérieure à la tension de flottement, le danger résultant d'un emballement
thermique augmente et la correction de la tension en fonction de la température de la batterie
devient encore plus impérative.
Le fabricant de l'élément ou du monobloc doit fournir les valeurs de référence appropriées pour
ladite compensation au niveau des éléments/monoblocs (courbe).
Le fabricant du système de batterie doit déterminer le nombre optimal d'éléments/monoblocs
permettant de respecter au mieux les limites de tension au niveau du train comme cela est
spécifié dans le Tableau 1 de l'IEC 62973-1:2018, et comme cela est représenté dans la
Figure 5 et le Tableau 4, sur la base de la conception réelle de la batterie.
Le fabricant de la batterie doit spécifier les conditions sous lesquelles une charge rapide doit
être initiée et interrompue.
Figure 5 – Rapport graphique température/tension en charge rapide

Tableau 4 – Niveaux de référence de tension et de température en charge rapide
Point de U en T de la Courbe de compensation Conditions Intervalle minimal
référence V/éléme batterie de la tension par K en spécifiées pour entre deux charges
nt en °C 0,00Y V/K en cas d'écart l'initiation ou rapides spécifié en
avec la température de l'interruption d'une heures ou en
référence de 25 °C charge rapide événements
4 U T
4 4
À fournir par le fabricant À fournir par le À fournir par le
5 U T (25 °C)
de l'élément ou du fabricant du système fabricant du
5 5
monobloc de batterie système de batterie
6 U T
6 6
T et T sont le résultat du point de consigne (25 °C) et de la courbe.
4 6
La surveillance de la température indiquée au Tableau 4 doit être conforme au Tableau 1.
4.4.3 Performances de décharge
4.4.3.1 Généralités
L'exigence de décharge du ou des profil(s) de charge spécifié(s) doit être respecté.
4.4.3.2 Profil de charge
Le profil de charge reflète l'exigence de courant et/ou de puissance réelle et/ou de charges
résistives par rapport au temps de la batterie auxiliaire, dans une application en matériel roulant.
Le profil de charge doit être associé à une plage de températures de service (températures
maximales et minimales spécifiées par l'intégrateur système ou l'utilisateur final, conformément
au 4.4.5 de l'IEC 62973-1:2018) et à des limites de tension du système. Les profils types de
charge de l'IEC 62973-1:2018 sont fournis à titre purement informatif.
Un tel profil de charge peut intégrer des exigences aux durées prolongées de décharge, aux
performances à des températures basses ou élevées et à d'autres paramètres tels que le niveau
de capacité le long de la durée de vie en service.
L'intégrateur système ou l'utilisateur final doit fournir ces profils de charge et les conditions
associées.
4.4.4 Conservation de la charge (autodécharge)
Les batteries perdent en capacité lorsqu'en sont stockées en circuit ouvert. Cette perte est
quantifiée selon les conditions normalisées de l'article pertinent relatif aux essais de
l'IEC 60896-21:2004.
Le fabricant de la batterie doit fournir des directives concernant la durée maximale possible de
stockage en circuit ouvert avant qu'une recharge, telle que spécifiée pour une telle tâche, ne
devienne nécessaire. L'influence de la température de stockage doit être fournie par le fabricant
de la batterie.
4.4.5 Exigences de dimensionnement de la batterie
Le choix d'une batterie capable de satisfaire aux besoins énergétiques d'un matériel roulant en
tant que source d'énergie auxiliaire (c'est-à-dire son dimensionnement) doit être réalisé par le
fabricant du système de batterie.
Les paramètres requis de dimensionnement sont répertoriés au Tableau 5 et doivent être
fournis par l'intégrateur système ou l'utilisateur final.
...