Interpretation of the third edition of North American Standard UL 2056:2020 of power bank
On August 20, 2020, the North American Standard UL 2056 of charging treasure was released the third edition, which was greatly updated. The standard scope of application has been adjusted, and mobile power supply integrated into products such as bags and bags is added. The test contents have changed greatly from UL 2054 battery pack unit test and ul2056 supplementary test to now the independent evaluation of mobile power supply as a complete system.
Changes in the scope of application of the standard:
1. Structural requirements: internal / external circuit connection mode, electrical insulation test, shell packaging requirements, etc.
This outline of investigation specifies requirements and tests for the safety of power banks using lithiumion batteries as the energy source, with input and output voltages not exceeding 20 Vdc.
2. The circuit protection requirements have been increased: the test requirements for the temperature, voltage and current protection of the internal cell, especially when the allowable charging range specified by the manufacturer exceeds 10-40 ° C, the relevant tests also need to be evaluated at high and low temperatures.
NOTE 1 Power banks integrated (removable only) in luggage, carrying cases, bags, packs, etc. are within the scope of this outtine of investigation.
Content change of standard terms:
1. Structural requirements: internal / external circuit connection mode, electrical insulation test, shell packaging requirements, etc.
2. The circuit protection requirements have been increased: the test requirements for the temperature, voltage and current protection of the internal cell, especially when the allowable charging range specified by the manufacturer exceeds 10-40 ° C, the relevant tests also need to be evaluated at high and low temperatures.
Unless othenwise specified, tests are carried out under the most unfavorable conditions of intended use inan ambient temperature of 20 +5°C. However, if the manufacturer recommends charging at temperatures outside the range of 10 - 40°C, the ambient temperature for testing is as follows:
- If the battery is recommended to be charged at a minimum ambient temperature lower than 10°C,the test is also conducted at that minimum temperature +0/-5℃;
- If the battery is recommended to be charged at a maximum ambient temperature greater than 40°C, the test is also conducted at that maximum temperature +0/-5℃.
3. Capacity test requirements: the old version requires that the measured capacity value must be greater than the marked value, while the new version requires that the measured capacity value must be within 90% - 110% of the marked value.
7.2.1 Rated capacity
The capacity of power bank shall not be less than 90% or exceed 110% of the marked capacity rating.
4. Other updated or added test requirements: limited power test, vibration and mechanical shock test, temperature limit of components and contact surface, short circuit and overload test, overcharge test, etc.
7.2.3 Limited power source
The output available from any port shall comply with the limits of limited power output as noted in Table 7.3 or Table 7.4.
7.2.4 Vibration and mechanical shock
Vibration and mechanical shock encountered during transportation and use shall not cause fire, explosion,rupture, leakage or venting.
7.3 Abnormal operation
7.3.1 External short. circuit and overload
Short-circuiting of positive and negative terminals of the power bank shall not cause fire or explosion from the power bank or ignite the external fire indicators.
7.3.2 Overcharge
A power bank shall tolerate without fire or explosion an overcharging condition outside the cell manufacturer's specified operating region.