Safety Requirements for Portable Sealed Secondary Lithium Cells and Batteries — UL Adoption of IEC 62133-2
UL 62133 is UL’s adoption of the IEC 62133 series of standards for portable sealed secondary battery cells and batteries. It includes both Part 1 (nickel systems) and Part 2 (lithium systems), making them available as US nationally recognised test laboratory (NRTL) certifications. UL 62133 certification is the US market equivalent of EN 62133 in Europe and is widely required for portable lithium-ion battery packs in consumer and commercial products sold in North America.
Published by: UL Standards and Engagement
Based on: IEC 62133-2:2017 (lithium systems), IEC 62133-1:2017 (nickel systems)
Related standards: UL 2054 (US battery pack standard), UL 1642 (lithium cells)
Scope
UL 62133 applies to portable sealed secondary lithium cells and batteries for use in portable consumer and commercial applications. It covers the same test requirements as IEC 62133-2 — overcharge, over-discharge, short circuit, drop, mechanical shock, thermal abuse, and environmental tests — with UL NRTL certification marks providing US market recognition.
Key Requirements
Electrical Safety Tests
Tests include continuous low-rate overcharge (1 mA per mAh for 28 days), short circuit at 20 °C and 55 °C, and forced discharge. Cells and packs must not catch fire, explode, or rupture violently. Protection circuits must interrupt hazardous conditions within defined response times.
Mechanical and Environmental Tests
Drop tests (1 m onto hard surface), mechanical shock (6 g pulse), vibration, and temperature cycling tests verify structural and chemical integrity. Simulated abuse of protection circuits tests for unsafe conditions that could arise from protection component failure.
Disclaimer: This is not a definitive guide, just an indication and it is important that you always go back to the source for legislation.
References
- UL 62133, UL Standards