IEC 61960-4:2024

IEC 61960-4 ®
Edition 2.0 2024-07
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Secondary cells and batteries containing alkaline or other non-acid
electrolytes – Secondary lithium cells and batteries for portable applications –
Part 4: Coin secondary lithium cells, and batteries made from them
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IEC 61960-4 ®
Edition 2.0 2024-07
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Secondary cells and batteries containing alkaline or other non-acid
electrolytes – Secondary lithium cells and batteries for portable applications –
Part 4: Coin secondary lithium cells, and batteries made from them
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.220.99 ISBN 978-2-8322-9503-8
– 2 – IEC 61960-4:2024 CMV © IEC 2024
CONTENTS
FOREWORD .4
1 Scope .6
2 Normative references .6
3 Terms and definitions .7
4 Parameter measurement tolerances .8
5 Cell designation and marking.8
5.1 Cell designation .8
5.2 Marking . 10
5.2.1 General . 10
5.2.2 Small Swallowable cells or batteries . 11
6 Electrical tests . 11
6.1 General . 11
6.2 Charging procedure for test purposes . 12
6.3 Discharge performance . 13
6.4 Charge (capacity) recovery after long-term storage . 14
6.5 Endurance in cycles . 14
6.6 Cell or battery internal resistance (AC resistance) . 15
6.6.1 General . 15
6.6.2 Test – General . 15
6.6.3 Measurement . 15
6.6.4 Acceptance criterion . 16
7 Differentiation . 16
Annex A (normative) Requirements for secondary lithium watch batteries . 17
A.1 General . 17
A.2 Physical requirements. 17
A.2.1 Symbols and shape of cell . 17
A.2.2 Dimensions and size codes . 17
A.3 Test methods for determining the resistance to leakage . 18
A.3.1 Preconditioning and initial visual examination . 18
A.3.2 High temperature and humidity test . 18
A.3.3 Test by temperature cycle . 19
A.4 Visual examination and acceptance criteria . 19
A.4.1 Preconditioning . 19
A.4.2 Magnification . 19
A.4.3 Leakage levels and classification . 19
A.4.4 Acceptance conditions . 20
Annex B (informative) Guidelines for designers of equipment using lithium batteries . 21
Bibliography . 22
List of comments . 23

Figure 1 – Dimensional characteristics .9
Figure 2 – Sample sizes and sequence of tests . 12
Figure A.1 – Dimensional drawing. 17
Figure A.2 – Test by temperature cycles . 19

Table 1 – Electrochemical systems in current practical use .9
Table 2 – Examples of recommended generally used upper limit charge voltage . 13
Table 3 – Recommended end-of-discharge voltage limit Example of generally used
lower limit of end-of-discharge voltage . 14
Table 4 – Minimum number of cycles . 15
Table A.1 – Dimensions and size codes for watch batteries . 18
Table A.2 – Storage conditions . 18
Table B.1 – Equipment design guidelines . 21

– 4 – IEC 61960-4:2024 CMV © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SECONDARY CELLS AND BATTERIES CONTAINING ALKALINE OR
OTHER NON-ACID ELECTROLYTES – SECONDARY LITHIUM CELLS
AND BATTERIES FOR PORTABLE APPLICATIONS –

Part 4: Coin secondary lithium cells, and batteries made from them

FOREWORD
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This commented version (CMV) of the official standard IEC 61960-4:2024 edition 2.0
allows the user to identify the changes made to the previous IEC 61960-4:2020
edition 1.0. Furthermore, comments from IEC SC 21A experts are provided to explain the
reasons of the most relevant changes, or to clarify any part of the content.
A vertical bar appears in the margin wherever a change has been made. Additions are in
green text, deletions are in strikethrough red text. Experts' comments are identified by a
blue-background number. Mouse over a number to display a pop-up note with the
comment.
This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.

IEC 61960-4 has been prepared by subcommittee 21A: Secondary cells and batteries
containing alkaline or other non-acid electrolytes, of IEC technical committee 21: Secondary
cells and batteries, in cooperation with ISO technical committee 114: Horology. It is an
International Standard.
This second edition cancels and replaces the first edition published in 2020. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the pr
...