ISO 7176-31:2023

INTERNATIONAL ISO
STANDARD 7176-31
First edition
2023-05
Wheelchairs —
Part 31:
Lithium-ion battery systems and
chargers for powered wheelchairs —
Requirements and test methods
Fauteuils roulants —
Partie 31: Systèmes de batteries lithium-ion et chargeurs pour
fauteuils roulants motorisés — Exigences et méthodes d'essai
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Lithium-ion batteries .3
4.1 Battery performance and safety requirements . 3
4.1.1 General . 3
4.1.2 Fire . 4
4.1.3 Battery cyclic endurance . 4
4.2 Requirements for battery management systems . 4
4.2.1 General . 4
4.2.2 Functional requirements . 5
4.2.3 Electromagnetic compatibility (EMC) . 5
4.2.4 Climatic tests . 5
5 Requirements for the battery charging system . 6
5.1 Charger connector . 6
5.1.1 General . 6
5.1.2 XLR battery charger connector . 6
5.1.3 XLR wheelchair charger connector . 6
5.2 Battery charger function . 7
5.2.1 Requirements . 7
6 Instructions for use . .8
6.1 Battery charger . 8
6.2 Battery . 8
7 Battery labelling. 9
8 Test report . 9
Bibliography .10
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 173, Assistive products, Subcommittee SC 1,
Wheelchairs.
A list of all parts in the ISO 7176 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
This document was developed to standardize requirements for use of lithium-ion batteries in
wheelchairs.
Lithium-ion batteries provide performance enhancements relative to batteries with other chemistries,
but operation outside specified limits can pose unacceptable risks. It is important not to overlook
conditions that occur not only when charging using the wheelchair battery charger, but during
operation of the wheelchair, which can charge the battery system when decelerating and/or travelling
down a slope. In many cases, the wheelchair controller can be considered part of the battery system
and charging system combined.
v
INTERNATIONAL STANDARD ISO 7176-31:2023(E)
Wheelchairs —
Part 31:
Lithium-ion battery systems and chargers for powered
wheelchairs — Requirements and test methods
WARNING — The use of this document can involve hazardous materials, operations and
equipment. This document does not purport to address all of the safety or environmental
problems associated with its use. It is the responsibility of users of this document to take
appropriate measures to ensure the safety and health of personnel and the environment prior
to application of this document. Particular care should be taken regarding the possible emission
of toxic fumes resulting from lithium battery fires.
1 Scope
This document specifies requirements and test methods for lithium-ion batteries and battery systems
intended for use in electrically powered wheelchairs, and their charging systems.
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.
ISO 7176-8, Wheelchairs — Part 8: Requirements and test methods for static, impact and fatigue strengths
ISO 7176-14, Wheelchairs — Part 14: Power and control systems for electrically powered wheelchairs and
scooters — Requirements and test methods
ISO 7176-25:2022, Wheelchairs — Part 25: Lead-acid batteries and chargers for powered wheelchairs —
Requirements and test methods
IEC 60335-2-29:2016+Amd 1:2019, Household and similar electrical appliances — Safety — Part 2-29:
Particular requirements for battery chargers
IEC 60417, Graphical symbols for use on equipment — Registered symbols
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 62133-2, Secondary cells and batteries containing alkaline or other non-acid electrolytes - Safety
requirements for portable sealed secondary lithium cells, and for batteries made from them, for use in
portable applications - Part 2: Lithium systems
IEC 61960-3, Secondary cells and batteries containing alkaline or other non-acid electrolytes - Secondary
lithium cells and batteries for portable applications - Part 3: Prismatic and cylindrical lithium secondary
cells and batteries made from them
IEC 62619:2017, Secondary cells and batteries containing alkaline or other non-acid electrolytes - Safety
requirements for secondary lithium cells and batteries, for use in industrial applications
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
cell
battery cell
basic manufactured unit providing a source of electrical energy by direct conversion of chemical energy,
that consists of electrodes, separators, electrolyte, container and terminals, and that is designed to be
charged electrically
[SOURCE: IEC 62133-2:2017, 3.7]
3.2
battery pack
energy storage device, which is comprised of one or more cells or modules electrically connected
Note 1 to entry: Some battery management functions are, by necessity, integrated into the battery; others may
need to be integrated into the control and drive system.
Note 2 to entry: It may incorporate a protective housing and be provided with terminals or other interconnection
arrangement.
[SOURCE: IEC 62619:2017, 3.10, modified]
3.3
module
battery module
group of cells connected together either in a series and/or parallel configuration with or without
protective devices (e.g. fuse or PTC) and monitoring circuitry
[SOURCE: IEC 62133-2:2017, 3.9, modified]
3.4
lithium-ion battery
secondary battery with an organic solvent electrolyte and positive and negative electrodes which
utilize an intercalation compound in which lithium is stored
Note 1 to entry: A lithium ion battery does not contain lithium metal.
[SOURCE: IEV 482-05-07, modified]
3.5
battery management system
BMS
electronic system associated with a battery which has functions to maintain safety and prevent damage
3.6
battery system
battery
system which comprises one or more cells, modules or battery packs
Note 1 to entry: The battery system can have cooling or heating units.
[SOURCE: IEC 62619:2017, 3.11, modified]
3.7
cell imbalance
difference between cell conditions that can cause a hazard if allowed to progress
EXAMPLE Significant divergence between cell volta
...