IEC 60086-3:2021

FINAL
INTERNATIONAL IEC/FDIS
DRAFT
STANDARD 60086-3
ISO/TC 114
Primary batteries —
Secretariat: SNV
Voting begins on:
Part 3:
2021-06-21
Watch batteries
Voting terminates on:
2021-08-16
Piles électriques —
Partie 3: Piles pour montres
This draft is submitted to a parallel vote in ISO and in IEC.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
IEC/FDIS 60086-3:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. IEC 2021

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CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Physical requirements . 8
4.1 Battery dimensions, symbols and size codes . 8
4.2 Terminals . 11
4.3 Projection of the negative terminal (h ) . 11
5
4.4 Shape of battery . 11
4.5 Mechanical resistance to pressure . 12
4.6 Deformation . 12
4.7 Leakage . 12
4.8 Marking . 12
4.8.1 General . 12
4.8.2 Disposal . 13
5 Electrical requirements . 13
5.1 Electrochemical system, nominal voltage, end-point voltage and open-circuit
voltage . 13
5.2 Closed circuit voltage U (CCV), internal resistance and impedance . 13
cc
5.3 Capacity . 13
5.4 Capacity retention . 13
6 Sampling and quality assurance . 14
7 Test methods . 14
7.1 Shape and dimensions . 14
7.1.1 Shape requirement . 14
7.2 Electrical characteristics . 14
7.2.1 Environmental conditions . 14
7.2.2 Equivalent circuit – Effective internal resistance – DC method . 14
7.2.3 Equipment . 15
7.2.4 Measurement of open-circuit voltage U (OCV) and closed circuit
oc
voltage U (CCV) . 16
cc
7.2.5 Calculation of the internal resistance R . 17
i
7.2.6 Measurement of the capacity . 17
7.2.7 Calculation of the internal resistance R during discharge in case of
i
method A (optional) . 19
7.3 Test methods for determining the resistance to leakage . 19
7.3.1 Preconditioning and initial visual examination . 19
7.3.2 High temperature and humidity test . 20
7.3.3 Test by temperature cycles . 20
8 Visual examination and acceptance conditions . 20
8.1 Preconditioning . 20
8.2 Magnification . 21
8.3 Leakage levels and classification . 21
8.4 Acceptance conditions . 22

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IEC 60086-3:2021 © IEC 2021 – 3 –
Annex A (normative) Designation . 23
Bibliography . 24

Figure 1 – Dimensional drawing . 8
Figure 2 – Shape of battery. 11
Figure 3 – Shape requirement . 14
Figure 4 – Schematic voltage transient . 15
Figure 5 – Curve: U = f(t) . 16
Figure 6 – Circuitry principle . 16
Figure 7 – Circuitry principle for method A . 18
Figure 8 – Circuitry principle for method B . 19
Figure 9 – Test by temperature cycles . 20

Table 1 – Zinc systems L and S dimensions and size codes . 9
Table 2 – Lithium systems B and C dimensions and size codes . 10
Table 3 – Values of l . 11
1
Table 4 – Applied force F by battery dimensions . 12
Table 5 – Standardised electrochemical systems . 13
Table 6 – Test method for U (CCV) measurement . 17
cc
Table 7 – Test method A for U (CCV) measurement . 18
cc
Table 8 – Storage conditions for the recommended test . 20
Table 9 – Storage conditions for optional test . 20
Table 10 – Leakage levels and classification . 21

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

PRIMARY BATTERIES –

Part 3: Watch batteries

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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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 60086-3 has been prepared by IEC technical committee 35: Primary
cells and batteries, and ISO technical committee 114: Horology.
This fifth edition cancels and replaces the fourth edition published in 2016. This edition
constitutes a technical revision.
This publication is published as a double logo standard.
This edition includes the following significant technical changes with respect to the previous
edition:
a) reformatted Table 1 and Table 2. The reformatted tables are now divided by system.
Dimensional tolerances were changed when appropriate. Cell sizes were removed or added
based on the size prevalence in the market place;
were reformatted;
b) in Table 3 the minimum values of l
1
c) the minimum OCV for the S system in Table 5 was changed to 1,55 V.

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IEC 60086-3:2021 © IEC 2021 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
35/1467/FDIS 35/1470/RVD

Full information on the voting for the approval of this International Standard 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.
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/standardsdev/publications.
A list of all parts in the IEC 60086 series, published under the general title Primary batteries,
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 "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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INTRODUCTION
This part of IEC 60086 provides specific requirements and information for primary watch
batteries. This part of IEC 60086 was prepared through joint work between the IEC and ISO to
benefit primary battery users, watch designers and battery manufacturers by ensuring the best
compatibility between batteries and watches.
This part of IEC 60086 will remain under continual scrutiny to ensure that the publication is kept
up to date with the advances in both battery and watch technologies.
NOTE Safety information is available in IEC 60086-4 and IEC 60086-5.

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IEC 60086-3:2021 © IEC 2021 – 7 –
PRIMARY BATTERIES –

Part 3: Watch batteries



1 Scope
This part of IEC 60086 specifies dimensions, designation, methods of tests and requirements
for primary batteries for watches. In several cases, a menu of test methods is given. When
presenting battery electrical characteristics and/or performance data, the manufacturer
specifies which test method was used.
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 60086-1, Primary batteries – Part 1: General
IEC 60086-2, Primary batteries – Part 2: Physical and electrical specifications
IEC 60086-4, Primary batteries – Part 4: Safety of lithium batteries
IEC 60086-5, Primary batteries – Part 5: Safety of batteries with aqueous electrolyte
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60086-1 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
3.1
capacitive reactance
part of the internal resistance that leads to a voltage drop during the first seconds under load
3.2
capacity
electric charge (quantity of electricity) which a cell or battery can deliver under specified
discharge conditions
Note 1 to entry: The SI unit for electric charge is the coulomb (1 C = 1 As) but, in practice, capacity is usually
expressed in ampere hours (Ah).
3.3
fresh battery
undischarged battery 60 days maximum after date of manufacture

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3.4
ohmic drop
part of the internal resistance that leads to a voltage drop immediately after switching the load
on
4 Physical requirements
4.1 Battery dimensions, symbols and size codes
Dimensions and tolerances of batteries for watches shall be in accordance with Figure 1,
Table 1 and Table 2. The dimensions of the batteries shall be tested in accordance with 7.1.
The symbols used to denote the various dimensions in Figure 1 are in accordance with
IEC 60086-2:2021, Clause 4.
Dimensions in millimetres

Key
h maximum overall height of the battery
1
h minimum distance between the flats of the positive and negative contacts
2
h minimum projection of the flat negative contact
5
maximum and minimum diameter of the battery
d
1
d minimum diameter of the flat positive contact
2
d minimum diameter of the flat negative contact
4
NOTE This numbering follows the harmonization in the IEC 60086 series.
Figure 1 – Dimensional drawing

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IEC 60086-3:2021 © IEC 2021 – 9 –

Table 1 – Zinc systems L and S dimensions and size codes
Dimensions in millimetres
Height h /h
Diameter
1 2
a
Code
10 12 14 16 20 21 26 27 30 31 36 42 54
d
4
a
d
Tolerance
Code
1
Tolerances
0 0 0 0 0 0 0 0 0 0 0 0 0
−0,10 −0,15 −0,15 −0,18 −0,20 −0,20 −0,20 −0,20 −0,20 −0,25 −0,25 −0,25 −0,25
0
4 4,8 1,05  1,65 2,15
−0,15
0
5 5,8 2,6 1,05 1,25 1,65 2,15 2,70
−0,15
0
6 6,8 3,0  1,45 1,65 2,15 2,60
−0,15
0
7 7,9 3,5 1,25 1,45 1,65 2,10 2,60  3,10 3,60 5,40
−0,15
0
9 9,5 4,5 1,05 1,25 1,45 1,65 2,05  2,70  3,60
−0,15
0
11 11,6 6,0  1,65 2,05  3,05 3,60 4,20 5,40
−0,20
NOTE Open boxes in the above matrix are not necessarily available for standardization due to the concept of overlapping tolerances.
a
See Annex A.

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Table 2 – Lithium systems B and C dimensions and size codes
Dimensions in millimetres
Height h /h
Diameter
1 2
a
Code
12 16 20 25 30 32 50
d
4
a
d
Tolerance
Code
1
Tolerances
0 0 0 0 0 0 0
−0,15 −0,18 −0,20 −0,20 −0,20 −0,25 −0,30
0
10 10,0 3,0    2,50
−0,15
0
12 12,5 4,0  1,60 2,00 2,50
−0,25
0
16 16 5,0 1,20 1,60 2,00   3,20
−0,25
0
20 20 8,0 1,20 1,60  2,50  3,20
−0,25
0

23 23 8,0   2,00 2,50
−0,25
0
24 24,5 8,0     3,00  5,00
−0,25
NOTE Open boxes in the above matrix are not necessarily available for standardization due to the concept of overlapping tolerances.
a
See Annex A.

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