Sensata Technologies has announced the launch of its High-Efficiency Contactor (HEC), designed to simplify the transition from 400 to 800-V electric vehicle (EV) architectures. The HEC enables seamless compatibility with legacy and next-generation charging infrastructure, while delivering superior safety, efficiency, and simplified system integration.
As the EV industry accelerates toward 800-V systems for faster charging and improved efficiency, compatibility with the existing 400-V charging infrastructure remains a critical challenge. Sensata’s HEC addresses this by enabling battery reconfiguration between 400 and 800 V.
In addition to standard 400/800-V switching, the HEC uniquely supports independent access to either of the two 400-V battery packs, enabling critical functions, such as battery balancing and limp-home mode. This capability addresses key challenges in modern 800-V EVs, including pack imbalance due to aging or uneven usage, and the loss of drive capability if one pack fails.
By allowing selective isolation of each pack, the HEC helps extend battery life, improve reliability, and reduce the risk of stranding in critical situations.
The HEC integrates three high-voltage contactor poles into a patent-pending design featuring mechanically synchronized contacts, providing an inherently safe and highly efficient switching mechanism.
The design removes the risk of short circuits that can occur in traditional battery switching systems with multiple contactors, which may be caused by software errors, welded contacts, or mechanical shocks, resulting in best-in-class safety and reliability. Energy loss and heat generation are negligible due to its bi-stable design and ultra-low contact resistance (<50μΩ).
Features include:
- Flexible configuration: Supports standard battery configurations (Series-800 V, Parallel-400 V, Open-Isolated) and single-pack selection (A-only / B-only) for battery balancing and limp-home modes.
- Inherent safety: Unique mechanical design prevents incorrect switching, eliminating short-circuit risk.
- Reliable performance: Withstands short-circuit events up to 25 kA and mechanical shocks over 90 g.
- Lightweight: Reduces system component count by over 50%; no extra cooling or special equipment required.
- High efficiency: Bi-stable design requires no holding power; extremely low contact resistance (less than 50 µΩ) minimizes energy loss and heat generation.
Engineered for high-performance and safety-critical applications, the HEC supports continuous currents over 1000 A. Real-time diagnostics are enabled through an integrated ASIL-D compliant position sensor.
Beyond 400/800-V battery reconfiguration, Sensata’s HEC is also compatible with vehicle-to-grid (V2G) systems, megawatt charging, and the North American Charging Standard (NACS/J3400), making it a versatile solution for modern EV and energy ecosystems.
Filed Under: Charging, Technology News