Case Studies

Bed-of-Nails Battery Management System PCB Test Station

Posted in Automotive, Battery Pack Test Systems, Energy and Utilities, Green Technology, LabVIEW, Semiconductor, Test & Measurement Automation, Test Stand

Summary

DMC adapted our Battery Production Test (BPT) standard electrification solution to a user-friendly and cost-effective custom End-of-Line test system for a client's new Battery Management System (BMS) PCBs.

To deliver this solution, DMC developed an automated test system that incorporated a custom Bed-of-Nails fixture to connect to the client's PCBs and execute a custom developed validation test suite. The system incorporated Pickering hardware for battery emulation, NI hardware for signal measurement, and NI TestStand software for test sequence development.

Fig.1: BMS Test Stand with Bed-of-Nails Fixture

Fig.2: Bed-of-Nails Fixture Closeup

Fig.3: BPT Application Closeup

Solution

A leading battery company approached DMC for help developing a custom automated test system for their new BMS PCB manufacturing line. DMC expediently engaged with the client to design and develop a solution based on DMC’s proven Battery Production Test platform. Unique client requirements required adding cell simulation functionality, software flash/programming, and PCB validation tests to DMC's BPT standard platform.

Test Specification

The functional test specification required:

  • BMS firmware flashing
  • Cell emulation
  • Thermistor emulation
  • Temperature and voltage tests
  • Communication over CAN and serial buses
  • Analyzing LED status indicators

Each BMS test resulted in a report with metadata identifying the DUT, test system configuration, and test results with limits included.

Systems Engineering

DMC had to factor in many requirements including test accuracy, cycle time, operator ergonomics, and overall system envelope. DMC leveraged our internal fabrication shop and carefully selected external vendors like Pickering for robust hardware solutions. The software design leaned on DMC’s existing platforms and tools to minimize costs while maintaining performance and reliability.

DMC divided the hardware design into modular sub-systems: data acquisition box, Bed-of-Nails test fixture, and instrument rack. The rack design housed multiple Pickering LXI chassis containing cell simulation and thermistor cards. The interfaces between these sub-systems were well defined early in the design process, along with consistent communication to minimize design siloing.

Software Design

Software customizability was a major consideration for the client, DMC built upon its proven Battery Production Test (BPT) platform to meet client's software requirements. Some highlights include:

Conclusion

DMC delivered a robust and highly configurable system on a deadline, providing our client with BMS test capability ahead of their full battery pack assembly line. The solution detects manufacturing defects and provides traceable test results to each battery under test.

Learn more about DMC's Battery Production Test (BPT) System, check out this BMS Power HiL Test System, or contact us to discuss your next project.

Customer Benefits

  • Test System performs 751 individual health checks with a total average test time of 5 minutes and 18 seconds
  • Cost effective solution scoped directly to client needs
  • Flexible hardware and software architecture allows for functionality expansion as needed
  • Provides product traceability capabilities
  • Compact test stand design to optimize required plant floor space

Technologies

  • DMC BPT Software
  • Pickering Battery Emulation Hardware
  • NI cDAQ Platform Hardware
  • NI TestStand
  • NI LabVIEW
  • FEASA LED Analyzer