The Use of UL 1642 Impact Testing for Li-ion Pouch Cells

The industry demand for high-capacity cells with a small footprint is a result of demands for improved products and new applications. However, this presents challenges in terms of safety. While standards, such as UL 1642, have been developed for battery safety assessment, including impact testing, this paper shows that cell manufacturers are facing difficulties with UL 1642 safety tests. This is leading to alterations in the test procedures, where `golden samples' are tested, while production cells cannot pass the safety tests. This is a flaw in the process that is being accepted by UL. This paper reviews the UL 1642 standard and similar standards used in portable electronics, provides experimental support for the concerns, and presents recommendations.