Pull Force Evaluation of CCS Insulated End Caps

Insulated end caps installed on direct current (DC) pins of Combined Charging System (CCS) inlets have been identified as potential debris sources within electric vehicle supply equipment (EVSE) connectors, increasing the risk of electric shock and fire hazards. Although standards such as International Electrotechnical Commission (IEC) 62196-1:2022 specify mechanical pull-force requirements for these end caps, it remains unclear whether these requirements provide adequate robustness under real-world conditions. To address this concern, the National Charging Experience (ChargeX) Consortium's Hardware Task Force conducted evaluations of insulated end caps used in original equipment manufacturer (OEM) CCS inlets. This study assesses the performance of insulated end caps used in OEM CCS inlets, specifically those installed on DC pins, using the procedures defined in IEC 62196-1:2022 (Section Sign) 26.7 and SAE J3400, supplemented by additional experimental conditioning. To ensure relevance to real-world conditions, the National Laboratory of the Rockies (NLR) collaborated with charging network operators (CNOs) to guide the selection of charging inlet samples. Material analyses of the insulated end cap samples were conducted to confirm that the tested materials reflected the types and properties commonly observed in the field. The selected samples underwent temperature and humidity conditioning followed by pull-force testing to evaluate the end-cap integrity. Although SAE J3400 inlets were not directly tested due to limited diversity in available field data, the underlying end-cap principles between CCS and SAE J3400 are comparable, allowing the study's insights to be relevant to both technologies. Overall, this study provides a structured evaluation framework to inform potential refinements to mechanical pull-force requirements in charging standards.

• Record URL:
  • https://doi.org/10.2172/3014676
• Record URL:
  • https://www.nrel.gov/docs/fy26osti/96665.pdf
• Corporate Authors:

  Argonne National Laboratory

  Lemont, IL  United States 

  Idaho National Laboratory

  Idaho Falls, ID  United States 

  National Laboratory of the Rockies

  Golden, CO  United States 

  National Charging Experience Consortium (ChargeX Consortium)

  ,    

  Joint Office of Energy and Transportation

  ,    
• Authors:
  • Shinde, Saroj
  • Tolbert, Isaac
  • Meintz, Andrew
  • Moriarty, Kristi
• Publication Date: 2026-1

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; Photos; Tables;
• Pagination: 45p

Subject/Index Terms

• TRT Terms: Components; Electric vehicle charging; Performance tests; Standards; Structural connection
• Subject Areas: Energy; Highways; Maintenance and Preservation; Vehicles and Equipment;

Filing Info

• Accession Number: 01985223
• Record Type: Publication
• Report/Paper Numbers: NLR/TP-5400-96665, DOE/GO-102026-6942
• Contract Numbers: AC07-05ID14517; DE-AC36-08GO28308; DE-AC02-06CH113
• Files: TRIS, USDOT
• Created Date: Apr 7 2026 5:08PM