1、BS ISO12819:2009ICS 39.040.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDMethods of evaluationof the battery life of abattery-powered watchThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 May 2009 BSI 2
2、009ISBN 978 0 580 61921 2Amendments/corrigenda issued since publicationDate CommentsBS ISO 12819:2009National forewordThis British Standard is the UK implementation of ISO 12819:2009. Itsupersedes BS ISO 12819:1999 which is withdrawn.The UK participation in its preparation was entrusted to Technical
3、Committee STI/53, Specifications and test methods for jewellery andhorology.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct a
4、pplication.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS ISO 12819:2009Reference numberISO 12819:2009(E)ISO 2009INTERNATIONAL STANDARD ISO12819Second edition2009-03-15Methods of evaluation of the battery life of a battery-powered watch Mthodes dvaluation de lauto
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9、rofilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO
10、2009 All rights reservedBS ISO 12819:2009ISO 12819:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 General. 2 4.1 Parameters 2 4.2 Types of battery life 2 4.3 Operating mode 2 4.4 Environmental conditions 2 5 Curre
11、nt consumption of a watch. 2 5.1 Mean current consumed (Im) . 2 5.2 Capacity of the battery (C) . 2 5.3 Self-discharge currents (Ias, Iad) 3 5.4 Current consumption of additional functions (If) 3 6 Calculation of battery life. 4 6.1 Practical battery life (AP): method I 4 6.2 Theoretical battery lif
12、e (AT) 4 7 Labelling 4 Annex A (normative) Self-discharge currents. 5 Annex B (normative) Practical battery life, AP 6 BS ISO 12819:2009ISO 12819:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards b
13、odies (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 committee has been established has the right to be represented on that committee. International organizati
14、ons, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the
15、 ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of t
16、he member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 12819 was prepared by Technical Committee ISO/TC 114, Horology.
17、This second edition cancels and replaces the first edition (ISO 12819:1999) and Technical Corrigendum ISO 12819:1999/Cor.1:1999, which have been technically revised. BS ISO 12819:2009INTERNATIONAL STANDARD ISO 12819:2009(E) ISO 2009 All rights reserved 1Methods of evaluation of the battery life of a
18、 battery-powered watch 1 Scope This International Standard specifies two methods for determining the battery life of a battery-powered watch and specifies the labelling to be used by the manufacturers or the distributors to inform the users. According to the available information, either the theoret
19、ical battery life or the practical battery life must be calculated using the equations given in this International Standard. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For und
20、ated references, the latest edition of the referenced document (including any amendments) applies. ISO 6426-2, Horological vocabulary Part 2: Technical and commercial definitions IEC 60086-3, Primary batteries Part 3: Watch batteries 3 Terms and definitions For the purposes of this document, the ter
21、ms and definitions given in ISO 6426-2 and the following apply. 3.1 battery life operating duration of a battery-powered watch, as determined by the characteristics of the battery and the movement NOTE The battery life starts when the battery is inserted and starts powering the movement of the watch
22、 and lasts until the point when the voltage falls below the level required for operation and the watch stops. 3.2 practical battery life AP calculation of the battery life, taking in account the self-discharge current of the battery during storage and operation 3.3 theoretical battery life AT calcul
23、ation of the battery life assuming an ideal battery with no self-discharge of current BS ISO 12819:2009ISO 12819:2009(E) 2 ISO 2009 All rights reserved4 General 4.1 Parameters The following parameters influence the calculation: the type of battery used; the type of movement used; the operating and e
24、nvironmental conditions. 4.2 Types of battery life This International Standard considers two types of battery life, the practical battery life and the theoretical battery life. 4.3 Operating mode The operating mode may be normal or economic. Some watches have a device that permits the reduction of t
25、he power consumption during storage. The operating modes shall be described on the documents supplied with the watch. 4.4 Environmental conditions The values below are valid for normal environmental conditions as follows: a temperature of (28 2) C; a relative humidity of (50 10) %. 5 Current consump
26、tion of a watch 5.1 Mean current consumed (Im) The mean current, Im, is the average of currents consumed by the oscillator and the display of time of day function(s) excluding all additional functions. The mean current is expressed in microamperes (A). For a movement with an analogical display, the
27、consumption shall be measured over a large number of pulses of the motor. For a movement with a digital display, the consumption shall be measured when a mean number of digits is operating. 5.2 Capacity of the battery (C) The capacity of the battery used to determine the battery life of a watch shal
28、l conform to the value specified by the manufacturer of batteries and controlled by the watch manufacturer, in accordance with IEC 60086-3. The capacity, C, is expressed in milliampere hours (mAh). BS ISO 12819:2009ISO 12819:2009(E) ISO 2009 All rights reserved 35.3 Self-discharge currents (Ias, Iad
29、) 5.3.1 Self-discharge current in storage (Ias) When a battery is stored, it sustains an annual loss which affects capacity. Loss of capacity depends on the type of battery and the storage temperature and humidity. It is equivalent to the mean self-discharge current in storage, Ias, expressed in mic
30、roamperes according to Equation (1): sas8,76CI= (1) NOTE The value 8,76 is the ratio between the number of hours in the year (8 760) and the conversion rate from milliamperes to microamperes (1 000). The value DCsis usually supplied by the battery manufacturer. In the case of lack of information, th
31、e values given in Annex A shall be used. DCsis expressed in milliampere hours (mAh). 5.3.2 Self-discharge current in use (Iad) When the same battery discharges, the average self-discharge current, Iad, expressed in microamperes, may be different. It is determined by Equation (2): ad asI KI= (2) NOTE
32、 The value K depends on the type and size of the battery as well as the operating conditions (e.g. temperature). The value K is usually supplied by the battery manufacturer. In the case of lack of information, the values given in Annex A shall be used. 5.4 Current consumption of additional functions
33、 (If) The mean current, If, consumed over a day by an additional function is calculated by Equation (3): ff86 400itI= (3) where Ifis the mean current expressed in microamperes (A); ifis the additional current consumption due to the function, expressed in microamperes (A); t is the time of use of the
34、 function in one day, expressed in seconds (s). The usual values of t for additional functions used for the determination of Ifare those, expressed in seconds, that are usually mentioned in the users instructions for each product. In the absence of these values, in most cases the values given in Tab
35、le A.1 are conventionally selected. NOTE The values are approximate and may change over a wide range from one user to another. They are of interest only for comparison between products. BS ISO 12819:2009ISO 12819:2009(E) 4 ISO 2009 All rights reserved6 Calculation of battery life 6.1 Practical batte
36、ry life (AP): method I The practical battery life, AP, expressed in years, is determined by Equation (4), based on a linear decrease of the battery capacity: ()smad f8,76CnCAPI II=+(4) where n is the storage duration of the battery, expressed in years, from its manufacture until it is placed in the
37、watch. For comparison between products, the watch manufacturer shall use, at his own discretion, the values n = 1 or n = 0,5. For the battery life indication, the watch manufacturer shall take into consideration the intrinsic battery life, of which indicative values are given in B.3. Another method
38、of calculation for the practical battery life (method II) is described in B.4. 6.2 Theoretical battery life (AT) The theoretical battery life, AT, expressed in years, is determined by Equation (5): ()mf8,76CATI I=+(5) 7 Labelling The indication of the practical, AP, or of the theoretical, AT, batter
39、y life of a watch shall be expressed in years and, if necessary, this value shall be rounded to the half year immediately below the calculated value. However, if this value is below 2 years, it shall be expressed in months. The following wording shall be used in the documents supplied with the watch
40、: “The practical (or theoretical) battery life of this watch, determined in accordance with the method specified in ISO 12819, with a (producer, capacity) battery, reference ., is . years (or months).” BS ISO 12819:2009ISO 12819:2009(E) ISO 2009 All rights reserved 5Annex A (normative) Self-discharg
41、e currents A.1 General The following numerical values for calculating factors DCsand K (see 5.3) shall be used when information is not supplied by the battery manufacturer. A.2 Values for DCsDCs= 0,05C for silver oxide batteries; DCs= 0,02C for lithium batteries; where C is the nominal capacity of t
42、he battery. The factors 0,05 and 0,02 express the agreed yearly loss of capacity according to the type of battery. A.3 Values for K K = 1 for an unworn watch or one that is stored at a temperature 2,15 mm: 4 years; b) lithium batteries: 5 years to 10 years. NOTE The use of higher intrinsic lifetime
43、values is made at the discretion of the watch manufacturer. B.2 Statistical determination of the practical battery life (AP) For the determination of the practical battery life, AP, its statistical distribution should be considered. When the mean value of battery life is over “a” year, and the minim
44、um battery life is higher than “0,9a”, then the practical battery life to consider is “a” year. APmeanW a APmean ：mean of battery life APminW 0,9a APmin：minimum battery life The practical battery life is distributed according to a normal distribution, and the minimum battery life, APmin, is AP99,7 w
45、here AP99,7means practical battery life in which 99,7% of watches will work. BS ISO 12819:2009ISO 12819:2009(E) ISO 2009 All rights reserved 7Key X practical battery life Y frequency aAPmin. bAPmean. Figure B.1 Determination of practical battery life, AP, and distribution Relation between a and APme
46、anB.3 Practical battery life (AP) Method I Key X time Y capacity aStorage. bSelf-discharge. cCavailable. dCused. eConsumption and distribution. fCapacity of the battery and distribution. gAPmean. Figure B.2 Relation between practical battery life, AP, and capacity, C, of the battery BS ISO 12819:200
47、9ISO 12819:2009(E) 8 ISO 2009 All rights reservedWhen the self-discharge is constant, the decrease of the batterys capacity is also constant. Considering this assumption, Equation (B.1) is used: ()smad f8,76CnCAPI II=+(B.1) where Imis the mean current consumed by the movement; Iadis the self-dischar
48、ge current in use; Ifis the current consumption of additional functions. B.4 Practical battery life (AP) Method II When the self-discharge is proportional (by fixed rate) to the remaining capacity, Equations (B.2) and (B.3) should be considered for the determination of the practical battery life, AP
49、: ()()smf0,51ln 18,76CCAPII=+(B.2) ( )ln 1 n= (B.3) where n is the time, expressed in years; b is the proportional factor of self-discharge; a is the mean rate of self-discharge over n years. Equation (B.2) for the determination of the practical battery life, AP, is prepared by the following process. The ratio between capacity reduction and time (dc/dt) is expressed as addition of “self-discharge that is proportionate to the remaining capacity, C ” and “consumption current I
