HV Battery Disconnect Unit

Part No.: MPLCNL-HV-Battery-Disconnect-Unit
The system monitors the hybrid system and only connects the high voltage only when it is considered "safe and secure".


HV Battery Disconnect Unit

This training system focuses on the high voltage disconnection relays of the battery unit. The system monitors the hybrid system and only connects the high voltage only when it is considered ”safe and secure”. The accompanying Labsoft course explains this complex system.

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UniTrain: Battery Disconnect Unit in Hybrid and all Electric Vehicles

High-voltage battery disconnect unit (BDU)

The battery disconnect unit training system allows the design and operating principle for disconnecting a high-voltage battery from the on-board network to be investigated.


  • Experiment card with circuitry for experiments in Eurocard format
  • Labsoft browser, course software and additional virtual instruments
  • Storage case
  • Jumpers

Components on experiment card:

  • Electronic circuit for battery disconnect unit (BDU)
  • Measuring sockets
  • Fault simulation circuitry
  • Two battery blocks
  • Three relays
  • Microcontroller-based control
  • Service and maintenance plug
  • Ignition switch
  • Lamp to indicate when ignition is on
  • High-voltage fault switch
  • High-voltage fault indicator
  • Pilot disconnecting bridge
  • DC-link circuit capacitor
  • Load for on-board network
  • Display of on-board network load
  • Measurement sockets for battery blocks
  • Measurement sockets for on-board network

Training contents

  • Fundamentals of battery disconnect units
  • Compiling repair shop orders
  • Diagnostic functions
    • Reading out fault memory with a diagnostic tester
    • Classifying faults in vehicle systems
  • Function and design of a pilot line
    • Design of electric circuit
    • Principle of operation
    • Control
    • Circuit variants
  • Repair methods and conversations with customers
    • Selection of repair actions as specified by manufacturers
    • Working with spare part numbers
  • Investigation using measuring instruments
  • Effect of faults commonly seen in practice (simulated faults can be activated)
  • Course duration 7 hours approx.​​

Dimensions/ weight:

  • 100 x 170 mm (width x height)
  • 0.8 kg