On 14 April 2023 ANSI of the United States and the Standards Council of Canada (SCC) published ANSI/CAN/UL 2743:2023, the safety standard for portable energy storage power supplies. This new edition is a major revision of the previous UL 2743:2018 and UL 2743:2020 editions and contains a series of standard optimizations. The main updates are as follows:

1. The limits for hazardous voltage are redefined: for products used indoors only the safety voltage must not exceed 60 V dc or 42.4 V AC peak, and for products used outdoors it must not exceed 30 V dc or 21.2 V AC peak.

2. The maximum capacity to which UL 2743 applies is specified; products above the limit fall under UL 9540:

3. A definition of portable energy storage is added: a product that can be lifted and moved by one person without mechanical aids and that is not permanently connected to the power system. It may be of the following types:

(1) hand-held; or

(2) mobile, meeting the following conditions:

- weight not exceeding 18 kg and not fixed in place; or

- fitted with wheels or similar means so that an ordinary person can move it easily.

Note: for products powered by a detachable battery pack mounted on the product, the weight of the detachable battery pack must also be taken into account.

4. An exception to the flammability rating of plastic enclosures is added: if the product contains an internal metal or V-1 rated barrier, the plastic enclosure may have a minimum flammability rating of HB.

5. A new requirement for receptacle protection is added: protection of receptacles must meet the receptacle protection requirements of UL 1012.

6. The requirements for AC output receptacles are revised: the receptacle type must be either a 120 Vac, 15 A maximum two-pole receptacle, or a 120 Vac, 30 A maximum three-pole grounded receptacle meeting the following requirements:

- the receptacle circuit provides double insulation isolation between the grounded circuit and the mains input circuit, and must not supply tools that cut or contact live parts or wires; or

- the receptacle is provided with GFCI protection meeting UL 943.

7. New requirements are added for double-insulated products with functional earthing.

8. The maximum voltage of the car cigarette lighter output is revised to 24 V.

9. UL 2580 and UL 1973 are added as optional cell standards.

10. UL 1741 is added as an optional standard for evaluating inverters and boards.

11. A weight classification is added for the tilt test: products not exceeding 7 kg do not need to undergo the tilt test.

12. New requirements for wireless output are added: under normal and abnormal conditions the input power of the transmitting coil conversion circuit must not exceed 240 VA.

13. An energy hazard test and a low voltage limited energy circuit test are added.

14. The leakage current test is improved: for products without a mains input, the leakage current is measured between hazardous voltage circuits and the output earthing terminal or accessible metal parts.

15. The method for evaluating safety-related circuits is improved, and single component failure analysis is added as an optional approach.

16. It is clarified that the short-circuit resistance in the output short-circuit test must not exceed 10 mohm.

17. The overcharge test method is revised:

- for a universal charging port, charge at the maximum charging voltage and three times the maximum charging current for 1.25 hours, while considering single failure;

- for a non-universal charging port, charge at the maximum charging voltage and current of the external charger or internal charging circuit for 1.25 hours, while considering single failure.

18. New requirements are added for energy storage above 1 kWh:

- thermal runaway test of the battery pack;

- restriction of the place of use: it must not be used in bedrooms or habitable spaces.

19. A pull test for output cables and interconnection cables is added.

20. The low temperature pre-treatment for impact and drop tests is improved: for products with a minimum temperature below 0 degC, pre-treatment is carried out at the minimum temperature specified by the manufacturer.

21. Drop test requirements by weight are revised: products above 18 kg are dropped once from 0.9 m, and products not exceeding 18 kg are dropped three times from 0.9 m.

22. The rain test method is improved: for products with a fan, both the fan running and fan stopped conditions must be evaluated, and the acceptance criteria are revised so that water must not reach live parts or hazardous energy parts, and water ingress must not occur above these parts.

23. Two water protection ratings, rainproof and raintight, are added.

24. The test methods for car jump starters are improved.

25. It is clarified that flag labels must meet UL 969A.

26. The requirements for warnings and instructions are improved.