On June 25, 2021, UL official website released the latest amendment proposal to the UL2054 standard. The solicitation of opinions lasts until July 19, 2021. The followings are the 6 amendment items in this proposal:
- Inclusion of the general requirements for the structure of wires and terminals: the insulation of wires should meet the requirements of UL 758;
- Miscellaneous amendments to the standard: mainly misspelling correction, updates of cited standards;
- An addition of test requirements for adhesiveness: wiping test with water and organic solvents;
- Increase of the management methods of components and circuits with the same protection function in the electrical performance test: If two identical components or circuits work together to protect the battery, when considering a single fault, two components or circuits need to be faulted at the same time.
- Marking the limited power supply test as optional: whether the limited power supply test in Chapter 13 of the standard is carried out will be determined according to the manufacturer’s requirements.
- The modification of the 9.11 clause – the external short circuit test: the original standard is to use 16AWG (1.3mm2) bare copper Wire; modification suggestion: the external resistance of short circuit should be 80±20mΩ bare copper wire.
Influence of the proposal on battery design:
The Article 4 of the proposal may have most impact on the battery design: once modification suggestion on the fault of protection components and circuits is adopted, when protection is carried out through two identical circuits or components, another protection device needs to be added because the original ones need to be faulted. For example, in the overcharge test, if two same MOSFETs used for overcharge protection need to be faulted without any other overcharge protection designs working, the battery loses the overcharge protection and the test is impossible passed.
In summary, it is recommended that manufacturers adopt two different protection methods when designing battery to deal with possible subsequent changes.