UL 2272 CRD-2018 UL Standard for Safety Electrical Systems for Personal E-Mobility Devices - Section Paragraph Reference 9 16 24 26 27 28 Subject Clarification of Requirement for .pdf

1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared by UL LLC. It is normative for the applicable ULProduct Certification Program(

2、s); however, it is currently not part of the UL Standard(s) referencedbelow.Product Category (CCN): FKIS, FKIS7Standard Number: UL 2272Standard Title: Standard for Electrical Systems for Personal E-Mobility DevicesEdition Date: November 21, 2016Edition Number: 1Section / Paragraph Reference: 9, 16,

3、24, 26, 27, 28Subject: Clarification of Requirement for Personal E-mobility Device Powered byLead-Acid BatteryDECISION:9 Enclosures9.1 General9.1.5 For personal e-mobility devices powered by lead acid batteries, openings in the enclosure shall beconstructed to prevent accumulation of flammable gases

4、 that could lead to a hazardous condition fromconcentrations of hydrogen gas due to electrolysis of aqueous electrolytes greater than 25% of the LFLof hydrogen (equivalent to 1% concentration in a volume of air). Ventilation openings shall have aminimum opening area of:A=0.005NC5(cm2)Where:A = Total

5、 cross sectional area of ventilation holes required (cm2)N = Number of cells in batteryC5= Capacity of battery at the 5-h rate (Ah)Exception No. 1: The area of ventilation openings can be reduced if it can be demonstrated that there issufficient ventilation within the device to prevent hydrogen accu

6、mulations above 25% of the LFL ofhydrogen during overcharging test and imbalanced charging test. If this exception is used to determinethe compliance, a gas monitor suitable for detecting 25% of the lower flammability limit (LFL) of thehydrogen is to be used to measure the concentration of hydrogen

7、during the overcharge test andimbalanced charging test. A minimum of two sampling locations where concentrations may occur such asat vent openings or vent ducts shall be used for taking measurements.16 Protective Circuits and Safety Analysis16.1 The personal e-mobility devices protective circuitry s

8、hall maintain the cells within their specifiedoperating region for charging and discharging through the life of the device. If cell specified operatinglimits are exceeded, the protective circuitry shall limit or shut down the charging or discharging to mitigateexcursions beyond specified operating l

9、imits. Compliance is determined through a review of the cellspecifications and safety analysis of 16.2 and through the testing of this standard. If applicable to theUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULpersonal e-mobility device des

10、ign, the analysis and testing needs to evaluate the overcharge protectioncontrols ability to mitigate overcharge due to regenerative charging during use. Chargers withstandardized output connectors (e.g. USB connectors, 3-pin round dc “aviation” connectors that mayresult in the use of unspecified ch

11、argers shall not be considered as a reliable control to prevent anovervoltage or overcurrent condition.16.1.1 Since it is not practical to monitor and control individual cells of a monobloc battery, personale-mobility devices using lead-acid batteries as the power source shall protect the batteries

12、fromovercharge through voltage protection and from overheating through either current protection ortemperature protection or both.16.5 Devices relied upon for critical safety as noted in 16.4(a) - (b) shall minimally comply with theapplicable Environmental Stress tests described in Sections9-22ofthe

13、StandardforTests forSafety-Related Controls Employing Solid-State Devices, UL 991, or fully comply with appropriatefunctional safety requirements below. Devices solely relied upon for critical safety as noted in 16.4 (c)shall fully comply with appropriate functional safety requirements in one of the

14、 following standards asappropriate to the design of the electronic and software protection scheme:a) The Standard for Tests for Safety-Related Controls Employing Solid-State Devices, UL 991,or the Standard for Safety Functions Incorporating Electronic Technology, CSA-C22.2 No. 0.8,and the Standard f

15、or Software in Programmable Components, UL 1998;b) The Standard for Automatic Electrical Controls for Household and Similar Use - Part 1:General Requirements, UL 60730-1 or CAN/CSA-E60730-1; andc) The Standard for Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related Syst

16、ems - Part 1: General Requirements, IEC 61508-1, and all parts.Exception: For lead acid batteries, this requirement does not apply.24 Overcharge Test24.2 A fully charged sample is to be discharged at a 0.2 C constant discharge rate or a higher dischargerate permitted by the cell manufacturer to the

17、manufacturers specified EODV. The DUT is then subjectedto a constant current charging at the cell manufacturers maximum specified charging rate and under asingle fault condition in the charging protection circuitry that could lead to an overcharge condition.Protective devices that have been determin

18、ed reliable may remain in the circuit as noted in 20.5. Forinformation purposes, temperatures are to be monitored on the cell/module where temperatures may behighest. The output control circuitry of external chargers with standardized output connectors (e.g. USBconnectors, standardized round dc “avi

19、ation” connectors) that may result in the use of unspecifiedchargers shall not be considered as a reliable control to prevent an overcharging condition, and for thistest, the charger shall be replaced with a power supply capable of delivering 110% of the specified upperlimit charging voltage during

20、the test. Voltages on cells/cell blocks are to be monitored during the test andfor lead acid batteries, voltages on the batteries are to be monitored.24.3 The test is to be continued until the voltage has reached 110% of the specified upper limit chargingvoltage or the maximum obtainable charging vo

21、ltage (if the 110% of specified upper limit charging voltagecannot be reached due to remaining protection circuitry), and monitored temperatures return to ambientor steady state conditions and an additional 2 h has elapsed, or explosion/fire occur. If the DUT isoperational after the test, it shall b

22、e subjected to a minimum of one charge/discharge cycle at the cellmanufacturers maximum specified values per Section 22, Post Test Cycle. The test shall be followed byan observation period per 20.7.STANDARD NUMBER: UL 2272 -2-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBU

23、TION WITHOUT PERMISSION FROM UL24.6 As a result of the overcharge test, any of the following results in (a) - (e) below are considered anon-compliant result. See also Table 22.1 and Section 23, Results Criteria.a) E - Explosion;b) F - Fire;c) R - Rupture (enclosure);d) L - Electrolyte Leakage (exter

24、nal to enclosure); ande) S - Electric shock hazard (resistance below isolation resistance limits or dielectricbreakdown).For lead-acid battery, the maximum voltage measured on the battery shall not exceed the specified upperlimit charging voltage for the battery.For other batteries, the voltage limi

25、ts on the cells are not to exceed the specified upper limit chargingvoltage.26 Overdischarge Test26.5 As a result of the overdischarge test, any of the following results in (a) - (e) below are considered anon-compliant result. See also Table 22.1 and Section 23, Results Criteria.a) E - Explosion;b)

26、F - Fire;c) R - Rupture (enclosure);d) L - Electrolyte Leakage (external to enclosure); ande) S - Electric shock hazard (resistance below isolation resistance limits or dielectricbreakdown).Voltages on the cells are not to exceed the specified end of discharge voltage limits.For other batteries, the

27、 voltage limits on the cells are not to exceed the specified upper limit chargingvoltage.Exception: For personal e-mobility devices powered by lead-acid batteries, only the results in (a) (e) areapplied.27 Temperature Test27.4 The manufacturers specified limits (for lead-acid batteries: battery volt

28、age, battery current, andbattery temperature are measured; for other batteries: cell voltage, cell or cell block current and celltemperatures are measured) shall not be exceeded during the charging and discharging cycles.Temperatures measured on components shall not exceed their specifications. See

29、Tables 27.1 and 27.2for surface and component temperature limits.28 Imbalanced Charging TestSTANDARD NUMBER: UL 2272 -3-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL28.1 This test is to determine whether or not a DUT with series connected c

30、ells can maintain the cellswithin their specified operating parameters if it becomes imbalanced. For personal e-mobility devicespowered by lead acid batteries, this test is only applicable if there are series connected lead acid batteries.28.2 A fully charged DUT shall have all of its cells with the

31、 exception of one cell/cell block discharged toits specified fully discharged condition. The undischarged cells shall be discharged to approximately 50%of its specified state of charge (SOC) to create an imbalanced condition prior to charging. For DUTsemploying lead acid batteries connected in serie

32、s, one of the batteries is to be discharged toapproximately 50% of its specified state of charge (SOC).28.3 The DUT shall then be charged in accordance with the manufacturers specifications using thespecified charger and under a single fault condition in the charging protection circuitry. Protective

33、 devicesthat have been determined reliable may remain in the circuit as noted in 20.5. The voltage of the partiallycharged cells shall be monitored during the charging to determine if its voltage limits are exceeded. If theDUT is operational after the test, it shall be subjected to a minimum of one

34、charge/discharge cycle at themanufacturers maximum specified values per Section 22, Post Test Cycle.28.3.1 For DUTs powered by lead acid batteries, only temperatures on the batteries are monitored (notcell voltages), and the charging is to continue until ultimate results such as a protective device

35、activatesand temperatures on the batteries return to ambient or the maximum charging voltage is reached and anadditional 7 h has elapsed. If the DUT is operational after the test, it shall be subjected to a minimum ofone charge/discharge cycle at the manufacturers maximum specified values per Sectio

36、n 22, Post TestCycle.28.5 The maximum voltage limit of the cells shall not exceed the manufacturers specifications. In addition,any of the following results in (a) - (e) below are considered a non-compliant result. See also Table 22.1and Section 23, Results Criteria.a) E - Explosion;b) F - Fire;c) R

37、 - Rupture (enclosure);d) L - Electrolyte Leakage (external to enclosure); ande) S - Electric shock hazard (resistance below isolation resistance limits or dielectricbreakdown).Exception: For personal e-mobility devices powered by lead-acid batteries, only the results in (a) (e) areapplied.RATIONALE

38、 FOR DECISION:UL 2272 was developed primarily for the personal e-mobility devices powered with lithium ion batteriesbased on the energy density and market norms. Considering the lithium-ion hazards, the specified celloperating range for charging and discharging are required to be maintained through

39、the life of the device,which typically requires a battery management system to monitor and control the battery circuit.STANDARD NUMBER: UL 2272 -4-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULRecently, new personal e-mobility devices powere

40、d with lead-acid batteries are being developed toreduce the product cost. With the lead acid battery designs, only simplified protective devices wereprovided for the lead-acid batteries as they have considerably less energy than lithium ion batteries, area monobloc design, so individual cells are no

41、t monitored, and are less sensitive to certain abuseconditions.This certification requirement decision is written to address the specific safety of personal e-mobilitydevices powered with lead acid batteries. This CRD gives the clarification of the approach to certify thepersonal e-mobility device p

42、owered with lead acid batteries.Lead acid batteries can go into thermal runaway if they are overheated, which has occurred duringcharging conditions. Lead acid batteries can release hydrogen gas if overcharged. The lower flammablelimit for hydrogen is 4% concentration in air. If there are sparks or

43、hot parts in the vicinity of the batteryvent, its very easier to cause a fire or explosion. This hazardous gas release shall be addressed throughconstruction design and tests including overcharge test and imbalanced charging test. Additionally, thelead acid battery shall be protected from overvoltag

44、e or overheat condition during charging.For Lead acid batteries, their overall safety response is not as sensitive to exceeding their operating rangefor voltage and temperature when compared with lithium ion batteries. They have demonstrated moretolerance with less sophisticated controls in various

45、applications. This evaluation approach requires thatthe lead acid battery operating range be maintained during the normal temperature test and the voltagebe maintained during the overcharge test, but it is not required during other abnormal tests as long as noother hazards are presented as required

46、in the standard.Checking the available personal e-mobility devices in the market, most devices use the standardizedround dc “aviation” connectors as the charging inlet, such as 3 pins diameter 12 mm round dc connectors,which may result in the use of unspecified chargers on the market for the scooter

47、. In this condition, theexternal charger shall not be considered as a reliable control to prevent an overcharging condition.However, this can be also true for lithium ion systems with external chargers that utilize standardizedplugs, where the power supply can easily be swapped out for a non-specifi

48、ed supply. Some clarificationfor the overcharging test, to indicate the need to provide sufficient test charging power as well as the needto monitor voltage was added for all systems for clarification.Copyright 2018 UL LLCUL LLC, in performing its functions in accordance with its objectives, does no

49、t guarantee or warrant thecorrectness of Certification Requirement Decisions it may issue or that they will be recognized or adoptedby anyone. Certification Requirement Decisions are the opinion of UL LLC. in practically applying therequirements of the standard. They do not represent formal interpretations of the standard underAmerican National Standards Institute (ANSI) processes. UL LLC shall not be responsible to anyone forthe use of or reliance upon Certification Requirement Decisions by anyone. UL LLC shall not incur anyobligation or liability for damages, including