IEC 63563-3:2025

IEC 63563-3 ®
Edition 1.0 2025-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Qi Specification version 2.0 –
Part 3: Mechanical, Thermal, and User Interface

Spécification Qi version 2.0 –
Partie 3 : Mécanique, thermique et interface usager
ICS 29.240.99, 35.240.99 ISBN 978-2-8327-0537-7

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either
IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC copyright
or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local
IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Discover our powerful search engine and read freely all the
The advanced search enables to find IEC publications by a publications previews, graphical symbols and the glossary.
variety of criteria (reference number, text, technical With a subscription you will always have access to up to date
committee, …). It also gives information on projects, content tailored to your needs.
replaced and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published containing more than 22 500 terminological entries in English
details all new publications released. Available online and and French, with equivalent terms in 25 additional languages.
once a month by email. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer
Service Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC -  IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez
La recherche avancée permet de trouver des publications gratuitement tous les aperçus des publications, symboles
IEC en utilisant différents critères (numéro de référence, graphiques et le glossaire. Avec un abonnement, vous aurez
texte, comité d’études, …). Elle donne aussi des toujours accès à un contenu à jour adapté à vos besoins.
informations sur les projets et les publications remplacées
ou retirées. Electropedia - www.electropedia.org

Le premier dictionnaire d'électrotechnologie en ligne au
IEC Just Published - webstore.iec.ch/justpublished monde, avec plus de 22 500 articles terminologiques en
Restez informé sur les nouvelles publications IEC. Just anglais et en français, ainsi que les termes équivalents
Published détaille les nouvelles publications parues. dans 25 langues additionnelles. Egalement appelé
Disponible en ligne et une fois par mois par email. Vocabulaire Electrotechnique International (IEV) en ligne.

Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-
nous: sales@iec.ch.
- 2 - IEC 63563-3:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
QI SPECIFICATION VERSION 2.0 –
Part 3: Mechanical, Thermal, and User Interface
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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect
thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which may be
required to implement this document. However, implementers are cautioned that this may not represent the latest
information, which may be obtained from the patent database available at https://patents.iec.ch. IEC shall
not be held responsible for identifying any or all such patent rights.
IEC 63563-3 has been prepared by technical area 15: Wireless Power Transfer, of IEC
technical committee 100: Audio, video and multimedia systems and equipment. It is an
International Standard.
It is based on Qi Specification version 2.0, Mechanical, Thermal, and User Interface and was
submitted as a Fast-Track document.
The text of this International Standard is based on the following documents:
Draft Report on voting
100/4256/FDIS 100/4278/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.
The structure and editorial rules used in this publication reflect the practice of the organization
which submitted it.
This document was 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.
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.
- 4 - IEC 63563-3:2025 © IEC 2025
WIRELESS POWER
CONSORTIUM
Qi Specification
Mechanical, Thermal, and User
Interface
Version 2.0
April 2023
DISCLAIMER
The information contained herein is believed to be accurate as of the date of publication,
but is provided “as is” and may contain errors. The Wireless Power Consortium makes no
warranty, express or implied, with respect to this document and its contents, including any
warranty of title, ownership, merchantability, or fitness for a particular use or purpose.
Neither the Wireless Power Consortium, nor any member of the Wireless Power
Consortium will be liable for errors in this document or for any damages, including indirect
or consequential, from use of or reliance on the accuracy of this document. For any further
explanation of the contents of this document, or in case of any perceived inconsistency or ambiguity
of interpretation, contact: info@wirelesspowerconsortium.com.
RELEASE HISTORY
Specification Version Release Date Description
2.0 April 2023 Initial release of the v2.0 Qi Specification.

- 6 - IEC 63563-3:2025 © IEC 2025
Table of Contents
1  General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1 Structure of the Qi Specification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.5 Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.6 Power Profiles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2  Power Receiver design requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3  Mechanical design guidelines (Informative). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1 Power Transmitter Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Power Receiver Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Power Transmitter Product Alignment Aid. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.4 Power Receiver Product Alignment Aid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4  Interface Surface temperature rise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5  User Interface requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1 User interaction with a Power Transmitter Product. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.2 User interaction with a Power Receiver Product. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1 General
The Wireless Power Consortium (WPC) is a worldwide organization that aims to develop and
promote global standards for wireless power transfer in various application areas. A first
application area comprises flat-surface devices such as mobile phones and chargers in the
Baseline Power Profile (up to 5 W) and Extended Power Profile (above 5 W).
1.1 Structure of the Qi Specification
General documents
 Introduction
 Glossary, Acronyms, and Symbols
System description documents
 Mechanical, Thermal, and User Interface
 Power Delivery
 Communications Physical Layer
 Communications Protocol
 Foreign Object Detection
 NFC Tag Protection
 Authentication Protocol
- 8 - IEC 63563-3:2025 © IEC 2025
1.2 Scope
The QiSpecification, Mechanical, Thermal, and User Interface (this document) identifies basic
physical design requirements and guidelines for Power Transmitter and Power Receiver Products,
including product and system dimensions, alignment of the products, surface temperature rise, and
indications to the user.
1.3 Compliance
All provisions in the QiSpecification are mandatory, unless specifically indicated as recommended,
optional, note, example, or informative. Verbal expression of provisions in this Specification follow
the rules provided in ISO/IEC Directives, Part 2.
Table 1: Verbal forms for expressions of provisions
Provision Verbal form
requirement “shall” or “shall not”
recommendation “should” or “should not”
permission “may” or “may not”
capability “can” or “cannot”
1.4 References
For undated references, the most recently published document applies. The most recent WPC
publications can be downloaded from http://www.wirelesspowerconsortium.com.

1.5 Conventions
1.5.1 Notation of numbers
 Real numbers use the digits 0 to 9, a decimal point, and optionally an exponential part.
 Integer numbers in decimal notation use the digits 0 to 9.
 Integer numbers in hexadecimal notation use the hexadecimal digits 0 to 9 and A to F, and are
prefixed by "0x" unless explicitly indicated otherwise.
 Single bit values use the words ZERO and ONE.
1.5.2 Tolerances
Unless indicated otherwise, all numeric values in the QiSpecification are exactly as specified and do
not have any implied tolerance.
1.5.3 Fields in a data packet
A numeric value stored in a field of a data packet uses a big-endian format. Bits that are more
significant are stored at a lower byte offset than bits that are less significant. Table 2 and Figure 1
provide examples of the interpretation of such fields.
Table 2: Example of fields in a data packet
b b b b b b b b
7 6 5 4 3 2 1 0
(msb)
B
16-bit Numeric Data Field
B
(lsb)
B Other Field (msb)
B 10-bit Numeric Data Field (lsb) Field
Figure 1. Examples of fields in a data packet
16-bit Numeric Data Field
b b b b b b b b b b b b b b b b
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
B B
0 1
10-bit Numeric Data Field
b b b b b b b b b b
9 8 7 6 5 4 3 2 1 0
B B
2 3
- 10 - IEC 63563-3:2025 © IEC 2025
1.5.4 Notation of text strings
Text strings consist of a sequence of printable ASCII characters (i.e. in the range of 0x20 to 0x7E)
enclosed in double quotes ("). Text strings are stored in fields of data structures with the first
character of the string at the lowest byte offset, and are padded with ASCII NUL (0x00) characters
to the end of the field where necessary.
EXAMPLE: The text string “WPC” is stored in a six-byte fields as the sequence of characters 'W', 'P', 'C', NUL,
NUL, and NUL. The text string “M:4D3A” is stored in a six-byte field as the sequence 'M', ':', '4', 'D',
'3', and 'A'.
1.5.5 Short-hand notation for data packets
In many instances, the QiSpecification refers to a data packet using the following shorthand
notation:
/
In this notation, refers to the data packet's mnemonic defined in the QiSpecification,
Communications Protocol, and refers to a particular value in a field of the data packet.
The definitions of the data packets in the QiSpecification, Communications Protocol, list the
meanings of the modifiers.
For example, EPT/cc refers to an End Power Transfer data packet having its End Power Transfer
code field set to 0x01.
1.6 Power Profiles
A Power Profile determines the level of compatibility between a Power Transmitter and a Power
Receiver. Table 3 defines the available Power Profiles.
 BPP PTx: A Baseline Power Profile Power Transmitter.
 EPP5 PTx: An Extended Power Profile Power Transmitter having a restricted power transfer
()pot
capability, i.e. P = 5 W.
L
 EPP PTx: An Extended Power Profile Power Transmitter.
 BPP PRx: A Baseline Power Profile Power Receiver.
 EPP PRx: An Extended Power Profile Power Receiver.
Table 3: Capabilities included in a Power Profile
Feature BPP PTx EPP5 PTx EPP PTx BPP PRx EPP PRx
Ax or Bx design Yes Yes No N/A N/A
MP-Ax or MP-Bx design No No Yes N/A N/A
Baseline Protocol Yes Yes Yes Yes Yes
Extended Protocol No Yes Yes No Yes
Authentication N/A Optional Yes N/A Optional

- 12 - IEC 63563-3:2025 © IEC 2025
2 Power Receiver design requirements
A Power Receiver design shall include a Secondary Coil and an Interface Surface (see Figure 2). The
distance from the Secondary Coil to the Interface Surface of the Power Receiver Product shall not
exceed d = 2.5 mm across the bottom face of the Secondary Coil.
z
Figure 2. Secondary Coil assembly
Mobile
Device
d
z
Shielding
S‡…‘†ƒ”›
(optional)
Interface
‘‹Ž
Surface
3 Mechanical design guidelines (Informative)
3.1 Power Transmitter Product
For the best user experience with respect to wireless power transfer, it is recommended that:
 The Power Transmitter Product Interface Surface extends higher than its surroundings, or has
a size of at least 107 mm × 177 mm for the Baseline Power Profile.
For the Extended Power Profile, the recommended Power Transmitter Product Interface Surface
dimensions is at least 439 × 329 mm .
 The Power Transmitter Product Interface Surface is marked to indicate the location of its
Active Area(s)—e.g. by means of the logo or other visual marking, lighting, etc.
 In the case of stand-alone Power Transmitter Products, the Active Area is centered within the
Power Transmitter Product Interface Surface.
3.2 Power Receiver Product
The overall shape and size of a Power Receiver Product is dictated by its primary application. For
example, cell phones, headsets, and digital (still) cameras, all have substantially different form
factors. For the best user experience with respect to wireless power transfer, it is recommended
that the mechanical design of a Power Receiver Product follows the guidelines listed below to the
extent possible in relation to the primary application of the Power Receiver Product:
 The Power Receiver Product X, Y dimensions do not exceed 107 mm × 177 mm for the
Baseline Power Profile.
For the Extended Power Profile, Power Receiver Product X, Y dimensions do not exceed 439 × 329
mm .
 The Power Receiver Product Interface Surface is flat.
 The Power Receiver Product Interface Surface is marked to indicate the location of its Active
Area, e.g. by means of the logo or other visual marking.
 The location of the Active Area is centered within the Power Receiver Product Interface
Surface.
- 14 - IEC 63563-3:2025 © IEC 2025
3.3 Power Transmitter Product Alignment Aid
In order to ensure proper coupling between a Power Transmitter Product and a Power Receiver
Product, it is recommended that the Power Transmitter Product employs one or more of the
following Alignment Aids:
 A movable Active Area.
 A fixed visual marking of the Active Area on Interface Surface.
 Lighting that guides the user to align the Power Receiver Product.
 An audible signal that indicates when alignment is achieved.
 Tactile feedback that indicates when alignment is achieved.
3.4 Power Receiver Product Alignment Aid
In order to ensure proper coupling between a Power Transmitter Product and a Power Receiver
Product, it is recommended that the Power Receiver Product employs one or more of the following
Alignment Aids:
 An audible signal when alignment is achieved.
 Tactile feedback that indicates when alignment is achieved.
 A visual Response; e.g. a screen lighting up within 200 ms to indicate that power is received.
 An indication of wireless charging.

4 Interface Surface temperature rise
The Power Transmitter Product shall limit the top surface temperature of the thermal Test
Power Receiver (TPR-THERMAL-5W or TPR-THERMAL-15W) to at most 12 °C above the ambient
temperature, while the Test Power Receiver is operating at its desired Control Point for 1 hour in
an environment that is shielded against spurious thermal contributions due to air flow, radiation,
etc. It is recommended that the Power Transmitter Product limits the Interface Surface
temperature to at most 5 °C above the ambient temperature, while powering the Test Power
Receiver for 1 hour.
- 16 - IEC 63563-3:2025 © IEC 2025
5 User Interface requirements
The most important point of interaction between a user and a Power Transmitter Product is the
Interface Surface on which the Power Receiver Product is placed. Feedback about the power
transfer from the Power Transmitter Product and the Power Receiver Product can either reassure
the user that the power transfer process is going well or help the user to resolve a problem.
Section 5.1, User interaction with a Power Transmitter Product, provides recommendations about
useful indications. However, in specific use cases, such as in-vehicle chargers and public-venue
chargers, some of these recommendations may not be desirable or even possible.
5.1 User interaction with a Power Transmitter Product
A Power Transmitter Product should indicate the following conditions to a user:
 Indication to a user within 0.5 seconds that a Power Receiver Product or object is placed on
the Power Transmitter Product.
 Indication to a user whether power transfer or charging is in progress or not.
 Indication to a user whether power transfer or charging is complete.
 Indication to a user in case of an error of fault (in stand-by, at the initiation of, during or at the
completion of power transfer or charging).
 (Extended Power Profile only) Whether power transfer or charging occurs at a reduced rate.
NOTE: A Power Transmitter should indicate this condition if it has denied a Specific Request for
Guaranteed Load Power (Request = 0x01).
A Power Transmitter Product should indicate the following condition to a user:
 Indication to a user if a Foreign Object has been detected.
A Power Transmitter Product that is able to support multiple Power Receiver Products at the same
time should indicate each of the above conditions for each supported Power Receiver Product.
A Power Transmitter Product that can take input power from a USB Micro-B/Micro-AB or USB-C
receptacle should indicate to
...