UL 1642:2005 pdf download – Lithium Batteries
UL 1642:2005 pdf download – Lithium Batteries.
7 ConditionIng of Samples
7.1.1 Primary 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 man i .0 milliamperes. Batteries are to be discharged at room temperature. Cells with a liquid cathode such as thionyl chloride or sulfur oxide, shall also be conditioned by one-half discharge.
7.1.2 For solid electrolyte and other types of primary lithium 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 obfain the required discharge level in the minimum time.
7.2 Charge-dIscharge cycling
7.2.1 Secondary cells are to be conditioned at 25C (77f. Cells are continuously cycled as per the manufacturers 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 01 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.
8 Important Test Considerations
8.1 Some lithium 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 battery casings shall be monitored during the tests described in Sections 10. 12, 13, and 14. All personnel involved In the testing of lithium batteries are to be instructed never to approach a lithium 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.
11.8 Each test sample battery is to be discharged at a constant current of 0.2 GIl hour, to a manufacturer specified discharge endpoint voltage. The cell or battery is then to be charged with a constant maximum specitied 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 or Itie time required to reach the manufacturer’s specified end-of-charge condition, whichever is greater.
11.9 The cell/battery is to be tested without the assistance of overcurrent or thermal protective devices. unless such protective devices are integral to the cell construction or have been investigated for the purpose. When a resettable protective device operates during the test, the protector is to be allowed to reset as often as necessary and the test is to be continued until the appropriate charging time has been completed. but not less than 7 hours. A protective device that is not integral to the cell and that has not been investigated fo the purpose is to be short-circuited.
11.10 The samples shall not explode or catch fire.
12 Forced-Discharge Test
12.1 This test is intended for cells that are to be used in series-connected, multicell applications, such as 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 battery pack Is to be short circuited.