Inside EV Electrical Systems - Understanding Voltage and CAN

Inside EV Electrical Systems:

Understanding High Voltage, Low Voltage & CAN Networks

Key Takeaways

EV electrical systems are now a core design driver – not a supporting function
Modern EV performance, safety, and scalability are fundamentally driven by how well high-voltage, low-voltage, and communication systems work together as an integrated architecture.

High-voltage systems introduce entirely new design and safety challenges
Operating at 200–800V, EV systems require advanced insulation, thermal management, shielding, and connector design to prevent overheating, EMI, and safety risks like arcing.

Battery systems are complex, modular, and tightly managed
EV batteries are built from thousands of cells organized into modules and packs, with Battery Management Systems (BMS) continuously monitoring performance, safety, and health in real time.

Thermal management is critical to performance and safety
EV batteries must operate within a narrow temperature range – too hot increases degradation and risk, while too cold reduces performance and range – making cooling and heating systems essential.

Low-voltage systems still power the majority of vehicle functionality
Despite high-voltage propulsion, 12V/48V systems power critical components like control modules, safety systems, lighting, and infotainment – making them indispensable to overall vehicle operation.

DC-to-DC conversion replaces the alternator in EVs
Unlike ICE vehicles, EVs rely on DC-to-DC converters to step down high-voltage energy to power and charge low-voltage systems, ensuring continuous operation of core electronics.

CAN networks are the backbone of EV communication
With 50–150+ ECUs in modern vehicles, CAN networks enable real-time communication between systems, reducing wiring complexity and allowing flexible, scalable architectures.

Wire Harness design is becoming exponentially more complex
Increasing electrical content, tighter packaging constraints, and the addition of high-voltage requirements make wire harness engineering one of the most challenging aspects of EV design.

High-voltage harnesses require new engineering approaches
Larger cables, enhanced shielding, specialized connectors, and strict separation from low-voltage systems are required to manage power, safety, and electromagnetic interference.

Design for manufacturability is critical – and often overlooked
Common mistakes include undersized wiring, ignoring contact resistance, and creating harnesses that are difficult to install or service – leading to overheating, failures, and production delays.

Late-stage design changes are inevitable – but manageable with the right tools
Traditional workflows struggle with change management, but modern ECAD platforms enable real-time synchronization between schematics and harness designs, reducing rework and version control issues.

The future is integrated, model-based electrical system development
Moving away from fragmented, document-driven processes to connected ECAD platforms enables better design accuracy, traceability, and alignment between engineering and manufacturing.

Learn More & Get Started

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