EV Engineering & Infrastructure

  • News
  • Articles
  • Batteries
  • Charging
    • Wireless Charging
    • Vehicle-to-Grid (V2G)
  • Electrification
  • Testing and Safety
  • R&D
  • Learn
    • Learning Center
    • Tech Toolboxes
    • Webinars
  • Resources
    • Digital Editions
    • Diversity & Inclusion
  • Advertise
  • Subscribe

What are the challenges with high-voltage EV charging?

By Jeff Shepard | October 20, 2023

With existing battery technologies, higher voltages are the key to faster charging and reduced range anxiety. Current fast charging stations can deliver up to 600 Vdc and 400 A for a total power of 240 kW and charge an EV battery pack up to 80% in about 30 minutes. But that’s still too long to ensure widespread adoption of EVs. In part, that’s limited by today’s charger standards, like SAE J1772 in North America and IEC 61851 in Europe.

This FAQ begins with a brief review of the current status of high-voltage (HV) EV charging, looks at how EV battery packs are evolving to support HV and faster charging, looks at some of the challenges related to designing charger connectors that can handle currents of 500 A or more.

HV pack challenges
There are electrical and mechanical challenges to producing higher voltage battery packs. With a given battery chemistry, like today’s lithium-ion cells, a highly serialized cell count is necessary to increase the battery pack voltage. One mechanical challenge is that for a specific vehicle type, the space available for the battery pack is limited. Scaling up to 1.5 kV from today’s 800 V requires increasing the serial cell count and decreasing the parallel cell count to try and maintain the same physical size of the pack. But it’s not that easy. EV battery packs are highly complex and changing one design element can have cascading impacts on other aspects of the design (Figure 1)

Figure 1. EV battery packs are highly complex mechanical and electrical systems (Image: Volkswagen).

When moving from 800 V to 1.5 kV, increased clearance and creepage distances are needed to avoid insulation failure/partial discharge and meet the battery safety requirements of UL 2580. The increased spacing increases the ‘unused’ volume in the pack and can result in fewer cells fitting into the pack, reducing the effective energy storage, and potentially defeating the purpose of HV.

Another consideration is the need for HV contactors. Contactors are used in the inrush circuit to minimize inrush currents from the battery when the EV starts up and to disconnect the pack for safety when the EV is being serviced. Automotive-rated 1.5 kV contactors are larger and heavier than 800 V devices. More weight negatively impacts the EV range, providing another challenge to the development of HV packs.

High-current charging connectors
Designing HV chargers and batteries has its challenges. So does designing the connectors needed to deliver the power from the charger to the battery pack. One possible solution is to use larger conductors in the connectors to carry more current. That’s not necessarily a practical alternative. First, the larger conductors are heavier and less flexible and bring ergonomic challenges.


Figure 2. This liquid-cooled CCS connector can handle 500 A (Image: Phoenix Contact).

Second and more importantly, there’s already a connector standard for HV DC charging called the combined charging system (CCS). The CCS system is designed to enable a single inlet on an EV to handle either AC or DC charging as needed. Using a dedicated inlet for HV DC charging would increase EV weight, complexity, and cost. Instead, liquid-cooled CCS connectors have been developed that can handle 500 A at 1 kV and deliver 500 kW of charging power with a minimal temperature rise. The solution for 1.5 kV packs and charging infrastructure is still under consideration.

Summary
Next-generation HV EV charging is seen as the key to overcoming range anxiety and enabling widespread EV adoption. EV battery packs are highly complex electrical and mechanical systems. There are numerous challenges to overcome related to battery pack design, integration, and charging before 1.5 kV solutions become available.

References

  • Are Electric Vehicles with High Voltage Batteries Safe?, TDK
  • Engineering the Future of EV Charging Infrastructure, TE Connectivity
  • Key components for a new era – the battery system, Volkswagen
  • On-Board Chargers for High-Voltage Electric Vehicle Powertrains: Future Trends and Challenges, IEEE Open Journal of Power Electronics
  • The technology for fast charging stations, Phoenix Contact

You Might Also Like


Filed Under: Charging, FAQs, Featured
Tagged With: charging, electricvehicles, ev, fastcharging
 

Next Article

← Previous Article
Next Article →


 
“ee
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for EV professionals.

Featured Contributions

  • What role do thermal interface materials (TIMs) play in EV battery systems?
  • How evolving demands are driving innovations in EV battery safety and materials
  • How large EV battery packs can be safely recycled without disassembly
  • Changing from traditional powertrains to electrified machines requires optimizing the hydraulic system components to reduce energy consumption and extend vehicle range. What factors impact electric vehicle system design?
  • How to safely detect minute physical Li-ion battery flaws
More Featured Contributions

EE TECH TOOLBOX

“ee
Tech Toolbox: Internet of Things
Explore practical strategies for minimizing attack surfaces, managing memory efficiently, and securing firmware. Download now to ensure your IoT implementations remain secure, efficient, and future-ready.

Learning Center

EE Learning Center
Search Millions of Parts from Thousands of Suppliers.

Search Now!
design fast globle

Sponsored Content

  • Converting custom materials for EV applications
  • Advantech Powers Versatile Electric Vehicle Charging Systems

EV Training Days

ev
EV Engineering & Infrastructure
  • 5G Technology
  • Analog IC Tips
  • Battery Power Tips
  • Connector Tips
  • Design Fast
  • EDABoard Forums
  • Electro-Tech-Online Forums
  • Engineer’s Garage
  • Microcontroller Tips
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • Contact Us

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search EV Engineering & Infrastructure

  • News
  • Articles
  • Batteries
  • Charging
    • Wireless Charging
    • Vehicle-to-Grid (V2G)
  • Electrification
  • Testing and Safety
  • R&D
  • Learn
    • Learning Center
    • Tech Toolboxes
    • Webinars
  • Resources
    • Digital Editions
    • Diversity & Inclusion
  • Advertise
  • Subscribe
We use cookies to personalize content and ads, to provide social media features and to analyze our traffic. We also share information about your use of our site with our social media, advertising and analytics partners who may combine it with other information that you’ve provided to them or that they’ve collected from your use of their services. You consent to our cookies if you continue to use this website.OkNoRead more