Lithium Polymer Battery
UL1642 

What’s lithium polymer battery UL1642? UL is short for Underwriters Laboratories Inc. UL certification is a non-compulsory certification in the United States, mainly testing and certification of product safety performance, and its certification scope does not include the product’s EMC (electromagnetic compatibility) characteristics. It uses scientific testing methods to study and determine whether materials, devices, products, equipment, buildings, etc. are hazardous or harmful to life and property.
In short, it is mainly engaged in product safety certification and operating safety certification business. Its ultimate purpose is to obtain products with the right level of security for the market and to contribute to ensuring personal health and property safety.

Lithium Polymer Battery UL1642 Test Items

T.1 Short-Circuit Test;
T.2 Abnormal Charging Test;
T.3 Forced-Discharged Test
T.4 CrushTest;
T.5 ImpactTest;
T.6 Shock Test;
T.7 Vibration Test;
T.8 Heating Test;
T.9 Temperature Cycling Test;
T.10 Low Pressure (Altitude Simulation) Test;

Our company LiPol Battery Co. can help customers to apply the UL1642 test report. Each test takes one month after then you will get an officialUL1642 test report published by the third-party testing house (BCTC).

Lithium Polymer Battery UL1642 Performance

Lithium Polymer Battery UL1642 Test Samples

6.1 Fully charged primary cells or lithium polymer batteries and primary cells or batteries that have been conditioned by partial or complete discharge, or both, are to be used for the tests described in Sections 10-20. The number of samples to be used in each test for a primary technician-replaceable cell or lithium polymer battery is shown in Table 6.1. The number of samples to be used in each test for a primary user-replaceable cell or lithium polymer battery is shown in Table 6.3. When a group of cells or lithium polymer batteries of different sizes, but similar chemistries are involved, selected sizes representative of the range is to be tested.

6.2 Fully charged secondary cells or lithium polymer batteries and secondary cells or batteries that have been conditioned by charge-discharge cycling are to be used for the tests described in Sections 10 — 20. The number of samples to be used in each test for a secondary technician-replaceable cell or lithium polymer battery is shown in Table 6.2. The number of samples to be used in each test for a secondary user-replaceable cell or battery is shown in Table 6.4. When a group of cells or lithium polymer batteries of different sizes, and similar chemistries is involved, selected sizes representative of the range is to be tested.

6.3 Prior to conducting the testing in Section 17, the lithium polymer cell samples shall be pre-conditioned as outlined in 6.4 and 6.5.

6.4 For the heating test of Section 17, two sets of five lithium polymer batteries samples are to be fully discharged (i.e. to the manufacturer’s specified endpoint voltage). The samples are then placed in a test chamber and conditioned for 1 to 4 h (5 samples at the upper-temperature limit and 5 samples at the lower temperature limit of the operating region) as outlined in Table 6.3.

6.5 While still in the test chamber set at the temperature limits, the samples are charged (5 samples at the upper-temperature limit and 5 samples at lower temperature limit) at the specified maximum charging current and upper limit charging voltage per Table 6.3, using a constant voltage charging method. Charging is continued until the charge current is reduced to the specified end of charge conditions (i.e. 0.05 times the charge current).

Discharge Conditioning of Samples

7.1 Primary lithium polymer batteries are to be completely discharged by connecting their terminals through resistors that provide the desired level of discharge within 60 days. Completely discharged is considered to be the state in which the closed-circuit voltage has been reduced to less than 0.2 volts and the short-circuit current to less than 1.0 milliamperes. Lithium polymer batteries are to be discharged at room temperature. Cells with a liquid cathode such as thionyl chloride or sulfur dioxide shall also be conditioned by one-half discharge.

7.2 For solid electrolytes and other types of primary lithium polymer batteries that cannot be discharged within 60 days because of the small currents they inherently produce, longer discharge times plus discharge at higher temperatures may be used to obtain the desired level of discharge. The manufacturer’s recommended discharge procedures are to be followed so as to obtain the required discharge level in the minimum time.

7.3 Secondary cells are to be conditioned at 25°C (77°F). Cells are continuously cycled as per the manufacturer’s specifications. The specification shall be such that the full rated capacity of the cell is utilized and the number of cycles accumulated shall be at least equal to 25 percent of the advertised cycle life of the cell or cycled continuously for 90 days, whichever is shorter. Cycling is to be done either individually or in groups. Cells are to be recharged prior to testing as indicated in Table 6.2 and Table 6.4.

Important test considerations

8.1 Some lithium polymer batteries are capable of exploding when the tests described in Sections 10-20 are conducted. It is important that personnel be protected from the flying fragments, explosive force, sudden release of heat, and noise that results from such explosions. The test area is to be well ventilated to protect personnel from possible harmful fumes or gases.

8.2 As an additional precaution, the temperatures on the surface of the lithium polymer battery casings shall be monitored during the tests described in Sections 10, 12, 13, and 14. All personnel involved in the testing of lithium polymer batteries are to be instructed never to approach a lithium polymer battery while the surface temperature exceeds 90°C (194°F).

8.3 For protection, the Projectile Test, Section 20 is to be conducted in a room separate from the observer.

Temperature measurements

9.1 Temperatures are to be measured by thermocouples consisting of wires not larger than 24 AWG (0.21 mm2) and not smaller than 30 AWG (0.05 mm2) and a potentiometer-type instrument.

9.2 The temperature measurements on the batteries are to be made with the measuring junction of the thermocouple held tightly against the metal casing of the lithium polymer battery.

Lithium Polymer Battery UL1642 Electrical Tests

Short-Circuit Test

10.1 Each test sample lithium polymer battery, in turn, is to be short-circuited by connecting the positive and negative terminals of the lithium polymer battery with a circuit load having a maximum resistance load of 0.1 ohms. The battery is to discharge until a fire or explosion is obtained, or until it has reached a completely discharged state of fewer than 0.1 volts and the battery case temperature has returned to ±10°C (±18°F) of ambient temperature.

10.2 Tests are to be conducted at 20 ±5°C (68 ±9°F) and at 55 ±5°C (131 ±9°F). The lithium polymer batteries are to reach equilibrium at 20 ±5°C or 55 ±5°C, as applicable before the terminals are connected.

10.3 A lithium polymer battery is to be tested individually unless the manufacturer indicates that it is intended for use in series or parallel. For series or parallel use, additional tests on five sets of batteries are to be conducted using the maximum number of lithium polymer batteries to be covered for each configuration.

10.4 When an overcurrent or thermal protective device that has been investigated for the purpose actuates during the test, the test shall be repeated with the lithium polymer battery supply connected to the maximum load that does not cause the protective device to open. A protective device that has not been investigated for the purpose shall be short-circuited.

10.5 The samples shall not explode or catch fire. The temperature of the exterior cell or battery casing shall not exceed 150°C (302°F).

Abnormal Charging Test

11.1 Primary lithium polymer cells or lithium polymer batteries shall comply with 11.2— 11.7.

11.2 Cells or lithium polymer batteries conditioned in accordance with Tables 6.1 or 6.3, as applicable, are to be used for this test. The lithium polymer batteries are to be tested in an ambient temperature of 20 ±5°C (68 ±9°F).

11.3 Each test sample lithium polymer battery is to be subjected to a charging current of three times the current “l”, specified by the manufacturer by connecting it in opposition to a DC-POWER supply. The specified charging current is to be obtained by connecting a resistor of the specified size and rating in series with the lithium polymer battery. The best charging time is to be calculated using the formula:
t
𝑐=2.5C/3(l𝑐),
t
𝑐 is the charging time in an hour
C is the capacity of the cell/lithium polymer battery in ampere-hours
l
𝑐 is the maximum charging current, in amperes, specified by the manufacturer.
The minimum charging time is to be 7 hours.
11.4 When a non-resettable overcurrent or thermal protective device that has been investigated for the purpose operates during the test, the test is to be repeated at a charge current below the level that the protective device operates. When a resettable protective device operates during the test, the protector is allowed to reset to a total of 10 cycles; or until the appropriate charging time has been completed, but not less than 7 hours. A protective device that has not been investigated for the purpose is to be short-circuited.

11.5 The samples shall not explode or catch fire.

11.6 Secondary cells or batteries shall comply with 11.7—11.10.

11.7 Cells or lithium polymer batteries conditioned in accordance with Tables 6.2 or 6.4, as applicable, are to be used for this test. The lithium polymer batteries are to be tested in an ambient temperature of 20 ±5°C (68 ±9°F).

11.8 Each test sample lithium polymer battery is to be discharged at a constant current of 0.2c/hour, to a manufacturer specified discharge endpoint voltage. The lithium polymer cell or lithium polymer battery is then to be charged with a constant maximum specified output voltage and a current limit of three times the maximum charging current”l”, specified by the manufacturer. Charging duration is to be 7 hours of the time required to reach the manufacturer’s specified end-of-charge condition, whichever is greater.

11.9 The lithium polymer cell/battery is to be tested without the assistance of overcurrent or thermal protective devices unless such protective devices have been investigated for the purpose. When a non-resettable overcurrent or thermal protective device operates during the test, the test shall be repeated at an overcharging current below the level that the protection device operates. When a resettable protective device operates during the test, the protector is to be allowed to reset to a total of 10 cycles; or until the appropriate charging time has been completed, but not less than 7 hours. A protective device that has not been investigated for the purpose is to be short-circuited.

11.10 The samples shall not explode or catch fire.

Forced-Discharged Test

12.1 This test is intended for cells that are to be used in series-connected, multi-cell applications, such as lithium polymer battery packs.

12.2 A completely discharged cell is to be force-discharged by connecting it in series with fully charged cells of the same kind. The number of fully charged cells to be connected in series with the discharged cell is to equal the maximum number less one of the cells to be covered for series use. Five cells are to be completely discharged, at room temperature.

12.3 Once the completely discharged cell is connected in series with the specified number of fully charged cells the resultant lithium polymer battery pack is to be short-circuited.

12.4 The positive and negative terminals of the sample are to be connected with copper wire with a maximum resistance load of 0.1 ohms. The sample is to discharge until a fire or explosion is obtained, or until it has reached a completely discharged state of fewer than 0.2 volts and the lithium polymer battery case temperature has returned to ±10°C (18°F) of ambient temperature.

12.5 When an overcurrent or thermal protective device that has been investigated for the purpose operates during the test, the test shall be repeated with the lithium polymer battery supply connected to the maximum load that does not cause the protective device to open. A protective device that has not been investigated for the purpose shall be short-circuited.

12.6 The samples shall not explode or catch fire.

UL1642: Lithium Polymer Battery Mechanical Tests

Crush Test

12.1 This test is intended for cells that are to be used in series-connected, multi-cell applications, such as lithium polymer battery packs.

12.2 A completely discharged cell is to be force-discharged by connecting it in series with fully charged cells of the same kind. The number of fully charged cells to be connected in series with the discharged cell is to equal the maximum number less one of the cells to be covered for series use. Five cells are to be completely discharged, at room temperature.

12.3 Once the completely discharged cell is connected in series with the specified number of fully charged cells the resultant lithium polymer battery pack is to be short-circuited.

12.4 The positive and negative terminals of the sample are to be connected with copper wire with a maximum resistance load of 0.1 ohms. The sample is to discharge until a fire or explosion is obtained, or until it has reached a completely discharged state of fewer than 0.2 volts and the lithium polymer battery case temperature has returned to ±10°C (18°F) of ambient temperature.

12.5 When an overcurrent or thermal protective device that has been investigated for the purpose operates during the test, the test shall be repeated with the lithium polymer battery supply connected to the maximum load that does not cause the protective device to open. A protective device that has not been investigated for the purpose shall be short-circuited.

12.6 The samples shall not explode or catch fire.

Shock Test

15.1 The cell is to be secured to the testing machine by means of a rigid mount that supports all mounting surfaces of the cell. Each cell shall be subjected to a total of three shocks of equal magnitude. The shocks are to be applied in each of three mutually perpendicular directions unless it has only two axes of symmetry in which case only two directions shall be tested. Each shock is to be applied in a direction normal to the face of the cell. For each shock, the cell is to be accelerated in such a manner that during the initial 3 milliseconds the minimum average acceleration is 75 g (where g is the local acceleration due to gravity). The peak acceleration shall be between 125 and 175 g. Cells shall be tested at a temperature of 20 ± 5°C (68 ± 9°F).

15.2 The samples shall not explode or catch fire.

Vibration Test

16.1 A lithium polymer battery is to be subjected to simple harmonic motion with an amplitude of 0.8 mm (0.03 inch) [1.6 mm (0.06 inch) total maximum excursion].

16.2 The frequency is to be varied at the rate of 1 hertz per minute between 10 and 55 hertz and return in not less than 90 nor more than 100 minutes. The battery is to be tested in three mutually perpendicular directions. For a lithium polymer battery that has only two axes of symmetry, the lithium polymer battery is to be tested perpendicular to each axis.

16.3 The samples shall not explode or catch fire.

UL1642: Lithium Polymer Battery Environmental Tests

Heating Test

17.1 A lithium polymer battery is to be heated in gravity convection or circulating air oven with an initial temperature of 20 ±5°C (68±9°F). The temperature of the oven is to be raised at a rate of 5 ±2°C (9±3.6°F) per minute to a temperature of 130 ±2°C (266±3.6°F) and remain for 10 min. The sample shall return to room temperature (20±5°C) and then be examined. For lithium polymer batteries specified for temperatures above 100°C (212°F), the conditioning temperature shall be increased from 130 ±2°C (266±3.6°F) to 30±2°C (86±3.6°F) above the manufacturers maximum specified temperature. For a lithium polymer battery of lithium metal chemistry, the conditioning temperature shall be increased to a maximum of 170 ±2°C (338±3.6°F).

17.2 The samples shall not explode or catch fire.

Temperature Cycling Test

18.1 The lithium polymer batteries are to be placed in a test chamber and subjected to the following cycles: Raising the chamber-temperature to 70 ±3°C (158 ±5°F) within 30 minutes and maintaining this temperature for 4 hours. Reducing the chamber temperature to 20 ±3°C (68 ±5°F) within 30 minutes and maintaining this temperature for 2 hours. Reducing the chamber temperature to minus 40 ±3°C (minus 40 ±5°F) within 30 minutes and maintaining this temperature for 4 hours. Raising the chamber temperature to 20 ±3°C (68 ±5°F) within 30 minutes. Repeating the sequence for a further 9 cycles. After the 10th cycle, storing the lithium polymer batteries for a minimum of 24 hours, at a temperature of 20 ±5°C (68 ±9°F) prior to examination.

18.2 The samples shall not explode or catch fire.

Low Pressure (Altitude Simulation) Test

19.1 Sample lithium polymer batteries are to be stored for 6 hours at an absolute pressure of 11.6 kPa (1.68 psi) and a temperature of 20 ± 3°C (68 ± 5°F).

19.2 The samples shall not explode or catch fire as a result of the Altitude Simulation Test.

Lithium Polymer Battery: UL1642 Marking

Generals

A lithium polymer battery shall be legibly and permanently marked with:

a) The manufacturer’s name, trade name, or trademark or another descriptive marking by which the organization responsible for the product may be identified;

b) A distinctive (catalog or model) number or the equivalent;

c) The date or another dating period of manufacture not exceeding any three consecutive months.

If a manufacturer produces a battery at more than one factory, each lithium polymer battery-package shall have a distinctive marking to identify it as the product of a particular factory.

Critical Components

Material: e.g. external enclosure, PCB, closed-end connector, sleeves, cord anchorage, etc Components with winding: e.g. motor, transformer, magnetic coil, etc.

Other components: e.g. switch, thermostat, heater, plug, internal wire, capacitor, relay, varistor, etc.

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LiPol Battery Co., Ltd.

Bldg 4A, JunFeng Industrial Zone

ChongQing Rd, Shenzhen, China

info@lipolbattery.com

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