SIST EN 60952-2:2005

SLOVENSKI SIST EN 60952-2:2005

STANDARD
maj 2005
Letalske baterije – 2. del: Načrtovanje in konstrukcijske zahteve
Aircraft batteries -- Part 2: Design and construction requirements
ICS 29.220.20; 49.060 Referenčna številka
SIST EN 60952-2:2005(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD EN 60952-2
NORME EUROPÉENNE
EUROPÄISCHE NORM December 2004

ICS 29.220.20 ; 49.060 Supersedes EN 60952-2:1993


English version


Aircraft batteries
Part 2: Design and construction requirements
(IEC 60952-2:2004)


Batteries d'aéronefs Flugzeugbatterien
Partie 2: Exigences de conception Teil 2: Anforderungen für Planung
et de construction und Konstruktion
(CEI 60952-2:2004) (IEC 60952-2:2004)






This European Standard was approved by CENELEC on 2004-11-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60952-2:2004 E

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EN 60952-2:2004 - 2 -
Foreword
The text of document 21/612/FDIS, future edition 2 of IEC 60952-2, prepared by IEC TC 21,
Secondary cells and batteries, was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 60952-2 on 2004-11-01.
This European Standard supersedes EN 60952-2:1993.
The changes made involve the inclusion of those formats that can be standardised along with their
connectors and electrical interfaces.
It is recognised that additional data may be required by other organisations (national standards
bodies, AECMA, SAE, etc.). The present standard can be used as a framework to devise tests for
generation of the required data.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2005-08-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2007-11-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60952-2:2004 was approved by CENELEC as a European
Standard without any modification.
__________

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- 3 - EN 60952-2:2004
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60952-1 2004 Aircraft batteries EN 60952-1 2004
Part 1: General test requirements and
performance levels

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NORME CEI
INTERNATIONALE IEC
60952-2
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
2004-09
Batteries d'aéronefs –
Partie 2:
Exigences de conception
et de construction
Aircraft batteries –
Part 2:
Design and construction
requirements
© IEC 2004 Droits de reproduction réservés ⎯ Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
CODE PRIX
PRICE CODE V
Commission Electrotechnique Internationale
International Electrotechnical Commission
ɆɟɠɞɭɧɚɪɨɞɧɚɹɗɥɟɤɬɪɨɬɟɯɧɢɱɟɫɤɚɹɄɨɦɢɫɫɢɹ
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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60952-2 © IEC:2004 – 3 –
CONTENTS
FOREWORD.5
1 Scope.9
2 Normative references.9
3 Terms and definitions .9
4 General construction requirements.9
4.1 General purpose requirements for class I and II applications .9
4.2 General requirements.11
4.3 Installation considerations.11
4.4 Workmanship.11
5 Electrolytes.13
5.1 Electrolyte resistance.13
5.2 Electrolyte level.13
5.3 Leakage.13
6 Dissimilar metals.15
7 Corrosion prevention - Vented nickel-cadmium batteries only .15
8 Battery containers and components .15
8.1 Battery containers and covers.15
8.2 Electrical bonding.15
8.3 Cell jars and monoblocs.15
9 Venting arrangements.17
9.1 Battery requirements.17
9.2 Cell requirements.17
10 Inter-cell connectors for nickel-cadmium batteries .17
10.1 Special purpose inter-cell connections – non-removable.19
11 Handles.19
12 Latches.19
13 Materials and components for flooded nickel-cadmium batteries.19
14 Gas barriers and thermal runaway – nickel-cadmium only.21
15 Dimensions, mass, markings and identification requirements .21
15.1 Dimensions and mass.21
15.2 Colour.21
15.3 Marking.21
16 Heaters - Battery heating system .23
17 Electrical connectors - Strength of receptacle.25
18 Safety.25
19 Temperature monitoring.25
Annex A  Battery formats.27
Annex B (normative) Connectors .53

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60952-2 © IEC:2004 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
AIRCRAFT BATTERIES –
Part 2: Design and construction requirements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60952-2 has been prepared by IEC technical committee 21 :
Secondary cells and batteries.
This second edition cancels and replaces the first edition published in 1991. The changes
introduced in this edition involve the inclusion of those formats that can be standardised along
with their connectors and electrical interfaces.
The text of this standard is based on the following documents:
FDIS Report on voting
21/612/FDIS 21/616/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

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60952-2 © IEC:2004 – 7 –
It is recognised that additional data may be required by other organisations (national standards
bodies, AECMA, SAE etc.). The present standard can be used as a framework to devise tests
for generation of the required data.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 60952 consists of the following parts, under the general title Aircraft batteries:
Part 1: General test requirements and performance levels
Part 2: Design and construction requirements
1
Part 3: Product specification and declaration of design and performance (DDP)
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
___________
1)
The second edition of IEC 60952-3 (2004) replaces the first edition published in 1993 under the title: Aircraft
bateries – Part 3: External electrical connectors

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60952-2 © IEC:2004 – 9 –
AIRCRAFT BATTERIES –
Part 2: Design and construction requirements
1 Scope
This part of IEC 60952 defines the physical design, construction and material requirements for
nickel-cadmium and lead-acid aircraft batteries containing vented or valve-regulated cells or
monoblocs. The batteries are used for both general purposes and specific aerospace
applications.
The specific topics addressed in this part serve to establish acceptable quality standards
required to qualify a battery as airworthy and are divided into two classes (class I and II) as
defined in Clause 3 of IEC 60952-1.
A preferred range of aircraft batteries is specified in Annex A, but this part of IEC 60952 may
be used for other battery sizes, arrangements and ratings. For particular applications, other
design requirements may be stipulated. These will be in addition to the requirements of this
part and will be covered by specific documents.
2 Normative references
The following referenced documents are indispensable for the application 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 60952-1, Aircraft batteries – Part 1:General test requirements and performance levels
3 Terms and definitions
Clause 3 of IEC 60952-1 is applicable.
4 General construction requirements
Batteries complying with this standard shall be capable of meeting the requirements of
IEC 60952-1 upon commissioning in accordance with manufacturer instructions or as specified
in the product specification.
4.1 General purpose requirements for class I and II applications
Batteries designed for utilization in the aerospace environment shall be sufficiently robust and
shall withstand the rigors of normal application, handling, manoeuvres and the full range of
operating conditions permitted for the aircraft concerned.

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60952-2 © IEC:2004 – 11 –
4.2 General requirements
a) WARNING: Any change from the original battery manufacturer’s design and construction
requires re-qualification. During maintenance, do not mix cells or components of different
construction or manufacture in the same battery as this could result in a safety issue.
b) The terminal arrangements should be such as to obviate the possibility of incorrect
connection. The type of arrangements shall be selected from the examples shown in Annex
B.
c) The containers shall be constructed of impervious material. The battery manufacturer shall
declare the flammability characteristics of the outer containers.
4.3 Installation considerations
a) Location: Batteries and their containers shall be securely fixed in positions such that they
are easily accessible for inspection, replacement and necessary tests.
b) Temperature of electrolyte: The method of installation shall ensure that, under operating
conditions, the temperature of the electrolyte is maintained within the limits necessary for
satisfactory operation. This shall normally be achieved by suitable location of the batteries
within the aircraft.
c) Ventilation: Ventilation adequate for the prevention of dangerous concentrations of ignitable
or toxic gases shall be provided for the battery and compartment in which batteries are
installed. These arrangements shall take account of the quantities of gas likely to be
released under conditions of thermal instability of the battery.
d) Corrosion: Batteries should be accompanied on a tray which is resistant to corrosion by the
electrolyte. This tray should be so installed that it will not normally be removed with the
battery.
e) Flammability: Battery case material requirements may vary according to the location of the
battery within the aircraft. For example, batteries located within an area which may be
subject to a fuel fire shall be fire proof, batteries in crew or passenger compartments shall
be flame resistant, while batteries installed in flame resistant or fireproof battery boxes may
be flammable. Consideration must be given to toxic fumes given off by many “flame
retardant” materials when they burn
4.4 Workmanship
The battery shall be manufactured in such a manner as to be uniform in quality and shall be
free from defects that will affect life, functioning, and appearance. Batteries shall not have
loose contacts, improper moulding or fabrication, damaged or improperly assembled contacts,
peeling, flaking or chipping of plating or finish, mechanical damage due to testing
environments, nicks or burrs of metal parts of surfaces, nor improper or incorrect marking. A
description of the requirements is shown in Table 1. Upon delivery, prior to testing and
following testing the batteries shall be examined for compliance .

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60952-2 © IEC:2004 – 13 –
Table 1 – Workmanship requirements
Number Description Inspection
method
1 Electrical contact surfaces obstructed by insulation compounds Visual
2 Pitting or blow holes on the external cell container Visual
3 Electrolyte leakage Visual
4 Location and polarity of terminals not as specified Visual
5 Terminal and identification markings not as specified Visual
6 Terminal seals missing or defective Visual
7 Corrosion Visual
8 Particles of foreign material Visual
9 Welds containing blow holes, cracks, or slag inclusions Visual
10 Burrs on battery container or cover Visual
11 Improper colour on outside of container and cover Visual
5 Electrolytes
Those batteries designated “sealed” do not require the addition of distilled/de-ionised water to
the electrolyte during use or qualification testing. Maintainable types require the electrolyte to
be adjusted to a certain level within the cell. The addition of distilled/de-ionised water should
only be made when the battery is fully charged, as the level will vary depending upon its state
of charge. The manufacturer shall define the procedure for determining and adjusting the
electrolyte levels.
a) Potassium hydroxide electrolyte: nickel-cadmium batteries shall use an electrolyte
consisting of an aqueous solution of potassium hydroxide.
b) Sulphuric acid electrolyte: the electrolyte shall be an aqueous solution of sulphuric acid.
5.1 Electrolyte resistance
Components used inside the battery shall demonstrate resistance to electrolyte as required by
IEC 60952-1.
5.2 Electrolyte level
The cells of all flooded batteries shall have a clearly defined means of identifying the proper
electrolyte fill level. This may be by means of a permanent index mark in the filler neck, step,
notch, slot or some other obvious method. A specific method may be defined in the product
specification.
5.3 Leakage
Electrolyte leakage of batteries and components shall be evaluated according to the
requirements of IEC 60952-1.

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60952-2 © IEC:2004 – 15 –
6 Dissimilar metals
Where dissimilar metals are used in intimate contact, suitable protection against galvanic
corrosion shall be applied.
7 Corrosion prevention - Vented nickel-cadmium batteries only
After the battery has been assembled, all exposed metal surfaces of the cells, inter-cell
connectors, and associated hardware shall be coated with an electrolyte resistant, corrosion
preventive compound. Vent valve rubber sleeves, vent openings, and the interfaces between
current carrying surfaces shall not be exposed to the corrosion preventive film. The coating
shall be applied evenly and without voids.
8 Battery containers and components
The dimensions and locations of receptacles, hold-downs and vent tubes shall conform to the
format examples in Annex A.
8.1 Battery containers and covers
The battery container and cover shall be free of rough spots, pits, blowholes and other
deformations. The product specification may specify whether or not the lid shall be removable.
8.2 Electrical bonding
Where metallic hold downs are used, provision shall be made to provide a bare conductive
surface on all hold down bars, brackets, or attachment points, for electrical bonding with the
airframe unless detailed otherwise in the product specification. This may be accomplished by
leaving part of the outer 22 mm of the hold down bar uncoated or by spot facing the coating to
bare metal.
8.3 Cell jars and monoblocs
The cell container and cover shall be free of rough spots, pits, blowholes and other
deformations
They shall be made from insulating material which is resistant to the operating conditions. The
components shall be joined together by a permanent weld or adhesive which is resistant to
atmospheric pressure.
The cell container utilised in nickel-cadmium batteries shall be made of self-extinguishing
non-porous, alkali-resistant material, such as polyamide.
The cell container utilised in lead acid batteries shall be made of non-porous, acid-resistant
material, such as polypropylene, polystyrene and polycarbonate.

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60952-2 © IEC:2004 – 17 –
9 Venting arrangements
9.1 Battery requirements
The design of the battery shall employ a method of ambient air dilution of the gases generated
during overcharge. The purging system may be either by natural ventilation or by assisted
ventilation.
In natural ventilation, the battery container and/or cover shall have sufficient holes or louvres to
ensure gas dissipation in still air. Such holes or louvres shall be adequately protected to
prevent access by foreign objects.
For assisted ventilation, the liberated gases from all the cells shall pass into a venting
chamber, having ports for the purging air. The battery manufacturer shall declare compliance
with the appropriate clause in IEC 60952-1. There are two preferred methods of achieving a
purging air flow:
a) the entry of air into the battery is via an entry housing with an integral non-return valve. It
shall not be possible to connect a pipe to the inlet side of the valve. The air is taken from
the battery by a pipe connection;
b) the air is taken to and from the battery by pipe connections and the direction of ventilation
is immaterial.
The manufacturer shall declare compliance with 6.5 of IEC 60952-1.
9.2 Cell requirements
9.2.1 Vented filler cap for vented cell
Each cell shall be fitted with a vent filler cap made of non-conductive material, which is
resistant to electrolyte and equipped with a sealing device.
The vent filler cap shall contain a device to permit the escape of gas. For aerobatic use
specified vent filler caps can be used to prevent the escape of liquid when the battery is
inverted.
The vent filler cap shall fulfill its function in all specified tests, at the pressure defined by the
manufacturer.
9.2.2 Valve for valve regulated cell
Each cell shall be fitted with a valve designed to allow the escape of gas in case of abusive
conditions.
10 Inter-cell connectors for nickel-cadmium batteries
10.1 General
Exposed inter-cell connections shall be designed and installed in such a way as not to interfere
with the removal of the cell vented filler caps. Epoxy or other plastics shall not be used to cover
the internal connectors or their fasteners. The manufacturer shall provide details of the correct
torque setting for the inter-cell connectors for each type of battery supplied.
Inter-cell connectors may be designed to be either removable or non-removable at the request
of the purchaser. Non-removable connecting links are described in 10.2. All inter-cell
connectors shall conform to the following guidelines:

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60952-2 © IEC:2004 – 19 –
a) be constructed of adequate size to match the current capabilities of the battery;
b) be constructed so as to not create corrosion or reactions from dissimilar metals; and
c) be capable of withstanding exposure to electrolyte.
10.2 Special purpose inter-cell connections – non-removable
Certain styles of low-maintenance, limited-repair nickel-cadmium batteries may be requested
with "non-removable" inter-cell connectors. The mounting hardware for this type of application
prevents the removal of the individual cells for maintenance. The inter-cell connections shall
not interfere with the removal of removable charger harnesses and tamper-resistant hardware
shall not be used on receptacles or harnesses. To impede cell removal, the inter-cell
connectors used in limited repair batteries shall be attached to the cell posts by the use of
tamper-resistant means, such as tamper-resistant fasteners, that shall be difficult to remove
but which shall not injure the cell upon removal. Rivets, welding, or adhesive methods shall not
be used to attach the intercell connectors of limited repair batteries.
11 Handles
Each handle shall be capable of supporting the weight of the battery by a factor of at least 1,5
times the weight of the battery.
WARNING: Battery vent tubes are not intended for use as lifting handles.
Other requirements for battery lifting handles, if required, shall be defined in the product
specification and shall detail appropriate human factors such as:
a) provide sufficient space to be used with cold weather protection;
b) not restrict normal use by fouling ancillary equipment.
12 Latches
Latches may be used to fasten the battery cover to the container body by a system of catches
mounted on the container body and strikes mounted on the cover. The position of the latches
and mounting method may be defined in the product specification.
13 Materials and components for flooded nickel-cadmium batteries
For flooded nickel-cadmium batteries, aluminium, polycarbonate, or polyester shall not be used
in the construction of any nickel-cadmium battery, cell or component covered by this standard.
Except for the hold-down pad, neoprene shall not be used in the construction of any nickel-
cadmium battery, cell, or component covered by this specification. When specified by the
procuring activity or the qualification activity, the manufacturer shall supply a certification of
conformity of the material or component. In the absence of certification from the source, a
certificate of analysis or certified inspection data will be required.

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