SAE J3337_202607

This recommended practice (RP) presents a methodology to evaluate RESS Cells Closure Integrity (Leak Tightness) requirement. This RP applies to two types of RESS Cells, each containing liquid electrolyte: Lithium ion (Li-ion) Cells and Sodium ion (Na-ion) Cells. The Equivalent Channel Method is used as a suggested cell closure integrity requirement for a given RESS Cell design during its production and product validation phases. The Closure Integrity requirements intended to assure no electrolyte leakage and no excessive moisture ingress during the usage of these cells as part of the RESS (Battery Pack), which is crucial to assure the safety and performance of these RESS. This RP specifies non-destructive Integrity (leak) testing processes of the Cell Closure. It describes approved leak testing technologies, testing procedures, tooling requirements, and leak test systems validation/verification requirements. This document may be applied to RESS Cell Closure Integrity testing during their initial product validation and their in-line 100% of production integrity/leak testing. This RP applies to RESS Cells with rigid packaging (cylindrical or prismatic) or flexible packaging (pouch). The increasing adoption of electrified propulsion systems in vehicles, including plug-in electric vehicles (EVs) and hybrid electric vehicles (HEVs), has driven the demand for reliable energy storage solutions. These vehicles rely on Rechargeable Energy Storage Systems (RESS), which are comprised of multiple interconnected energy cells. The integrity of these RESS cells, particularly their Closure Integrity, is critical to ensuring the long-term safety and performance of the entire battery system. Given the critical nature of RESS Cell Closure Integrity, this recommended practice defines the necessary Closure Integrity (leak) requirements and provides guidelines for approved non-destructive leak testing methods, including the tooling and procedures required for these tests. This ensures that the RESS cell package remains free from electrolyte leakage and excessive moisture ingress, factors essential to the safety and operational efficiency of the vehicle.