ithium and lithium-ion batteries are an integral part of everyday life. They are small, lightweight and, due to a high energy density, offer a long life. Across industries, from medical to consumer electronics, industrial applications to transportation, the small, lightweight energy sources pack quite a punch, making them a popular choice for manufacturers everywhere.
Most lithium batteries used today are safe when designed, manufactured and used properly. However, if they have design defects, are comprised of low-quality materials, are assembled incorrectly, are used or recharged improperly, or become damaged, they can pose a risk. Additionally, because of their high energy density, lithium batteries are susceptible to overheating and can become a fire hazard. For these reasons, there are several safety standards that manufacturers need to apply when developing and using devices incorporating lithium batteries.
UN 38.3 has been adopted by regulators and competent authorities around the world, making it a requirement for global market access. The protocol includes identifying/classifying lithium batteries, testing/qualification requirements, design guidance/conditions, and packaging/shipping obligations.
- UN 3090 for lithium batteries and UN 3480 for lithium-ion batteries: Apply to cells shipped alone, batteries shipped alone, consignment of cells and batteries, modules or other incomplete battery sub-assemblies, power banks, powerpacks, and batteries shipped in a separate package from the device they power (even if the device and batteries are on the same consignment or shipment).
- UN 3091 for lithium batteries within a device and UN 3481 for lithium-ion batteries within a device: Apply to devices with batteries installed; devices packed with a battery in the same package, but not installed in the product; up to two spare batteries shipped in the same package as the device (i.e., one installed, two spares).
- Tests T1-T5, conducted on the same samples for all battery types in sequence:
- Altitude simulation (Test T1)
- Thermal properties (Test T2)
- Vibration (Test T3)
- Shock (Test T4)
- External short circuit (Test T5)
- Test T6, conducted on the primary and secondary cells, evaluates impact and crush
- Test T7, conducted on secondary batteries, assessing overcharge
- Test T8, conducted on the primary and secondary cells, assessing forced discharge
- Integrated batteries: Updated to allow testing of batteries within equipment.
- Disassembly: Allows for additional test criteria. We recommend any cases that may be considered “borderline” disassembly to be treated as test failures.
- Rechargeable batteries considerations: Changes to the cycling requirements reducing to 25 charge/discharge cycles prior to test, from 50 previously. Also updates testing tables to reflect these changes.
- Test summary: Now clearly defines “battery test summary,” as well as the requirement that the test summary “shall be made available.” Additionally, it notes the requirement for the name and title of the signatory as an indication of validity.
It is important to remember to get or create a test report summary, based on successful completion of UN 38.3 testing. These summaries must be made available from the shipper upon request. Obtain the test reports from cell vendors and subcontractors to complete the test summary for shipments, and maintain the supporting information.
It is important to understand the difference between the two standards and how you can determine which is best to use. Some (but not all) of the changes in IEC 62133-2 1st Edition include:
- Separate nickel (IEC 62133-1) and lithium (IEC 62133-2) chemistries
- Inclusion of coin cells, if internal AC impedance is <3.0 Ohm
- Inclusion of single fault conditions
- Changes to cell level requirements
- External short circuit now performed at +55˚C ambient
- Thermal abuse hold times have been changed
- The crush test 10 percent deformation condition has been removed
- End conditions changed for forced discharge, so they are not only time-based.
- Adjustments to battery level requirements
- External short circuit should be performed with single fault condition
- Different overcharge charge conditions than before
- Vibration and mechanical shock tests have been added back to standard
- Incorporation of vibration and mechanical shock testing, based on UN 38.3, with UN 38.3 tests moved to reference Annex E.
Other countries and markets may adopt the new standard with different timelines. Ultimately, the intended market and end-product will determine which standard to use. When in doubt, partner and consult with experts who can help determine the best path forward.
There are several testing requirements under the standard. For both user- and technician-replaceable batteries, requirements include electrical, mechanical and environmental tests. Specifically, they include assessments for short-circuiting, heating, temperature cycling, forced-discharge, impact, humidity, shock, vibration, drop tests, abnormal changing and altitude simulation. There are also considerations for fire-exposure, flaming particles, projectiles and explosion for user-replaced situations.
UL 2054, “Standard for Safety of Household and Commercial Batteries,” is a performance and safety standard for household and commercial batteries, covering portable rechargeable and non-rechargeable batteries in products. Specifically, the batteries covered in this standard consist of either a single electrochemical cell or two or more connected cells that create electrical energy through a chemical reaction, like lithium and lithium-ion batteries.
UL 2054 is specific to the battery. The safety of the product is covered by its applicable standard. The standard is intended to reduce the risk of fire or explosion when batteries are used in a product and when batteries are removed to be transported, stored or discarded. It includes testing requirements for performance, electrical considerations, temperature, mechanical assessments, battery enclosure and pack evaluations, and environmental tests.
Both UL 1642 and UL 2054 have marking requirements related to warnings about risk of fire, explosion and burns, and require the inclusion of instructions not to recharge, disassemble, crush or heat above certain points or to incinerate. The warning statements should also include instructions on disposal and instructions to call physicians or poison control if ingested. Products should also be marked regarding the use of lithium batteries and their risk, and instructions should include guidance on replacing and disposing of batteries.