High Efficiency Contactor (HEC) Enables Safe 400V/800V Battery Switching

    July 17, 2025
    Sensata Technologies’ High Efficiency Contactor reduces component count by over 50% while supporting advanced battery configurations.
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    © Sensata Technologies, Inc.
    High Efficiency Contactor (HEC) Enables Safe 400V/800V Battery Switching

    The High Efficiency Contactor (HEC) is a multifunction high-voltage contactor for 400/800V battery reconfiguration in electric vehicles. It allows 800V EV architectures to interface with 400V charging stations without requiring separate boost converters, simplifying vehicle design and reducing cost.

    The unit supports reconfiguration of dual 400V battery packs into 800V series or 400V parallel configurations, along with the ability to isolate and access a single pack independently. This feature enables limp-home mode and battery balancing to extend battery life and ensure continued drive capability in the event of partial pack failure.

    Three high-voltage poles are integrated in a mechanically synchronized, patent-pending design that eliminates the risk of incorrect switching sequences. This prevents short circuits caused by software faults, welded contacts, or mechanical shock. The bi-stable design minimizes energy loss by requiring no holding power, and ultra-low contact resistance—less than 50 µΩ—limits heat generation.

    The HEC is capable of supporting continuous current over 1,000 A and can withstand short-circuit events up to 25 kA. It also includes an integrated ASIL-D compliant position sensor to support real-time diagnostics. The unit is compatible with Vehicle-to-Grid systems, megawatt charging, and the North American Charging Standard (NACS/J3400), enabling broad use across modern EV and energy ecosystems.

    Features:

    • Enables 400 to 800V battery reconfiguration without a boost converter
    • Supports Series-800V, Parallel-400V, Open-Isolated, and single-pack operation
    • Bi-stable design with ultra-low contact resistance (<50 µΩ)
    • Inherently safe switching with mechanically synchronized contacts
    • Integrated ASIL-D compliant position sensor for real-time diagnostics
    • Continuous current capacity over 1,000 A
    • Short-circuit withstand rating up to 25 kA
    • Withstands over 90 g of mechanical shock
    • No active cooling or specialized equipment required
    • Compatible with V2G, MW charging, and NACS/J3400

    Sensata Technologies, Inc.
    Attleboro, MA
    (508) 236-3800
    sensata.com