DMC was approached by a battery pack manufacturer prepared to use the‘out of the box’ software provided with their new battery cycler to perform End-of-Line (EOL) battery test sequencing. After several discussions with DMC, they understood the value in procuring a more complete test solution, like DMC's Battery Production Test (BPT) system, that could directly control their battery pack’s low voltage interface and provide a safe disconnect mechanism between their battery cycler and the pack under test. They also appreciated the importance of fully integrating their new test system with their assembly plant’s MES database, PLC controls, and material handling systems; functionalies well beyond the capability of the simple software shipping with their battery cycler.
DMC started this project with a clear request to provide a BPT-based system within the Client's strict budget. DMC carefully analyzed their battery pack design, interfaces, and operating modes, and their overall testing requirements. This analysis revealed that the Client's battery pack interface was relatively low-complexity, and their initial testing needs were rather basic. Since their requirements did not necessitate the use of DMC’s more full-featured BPT composition (see this case study), we initiated a new, lower-cost design, leveraging existing DMC hardware control modules. The result was a simple modular concept for achieving the basic battery pack tests that this Client required, while also meeting their aggressive budget demands.
This basic, but very cost-effective, BPT implementation allowed the Client to optimize use of their capital budget by purchasing only the test capability they needed for their current product. However, since this solution leverages the BPT platform software and NI hardware, they can still achieve the flexibility required for later expansion if needed.
Hardware System
To achieve this new BPT design, DMC leveraged the modularity of the NI platforms that form the basis of the BPT software and hardware system. Switching out the more capable, but also more costly, NI PXI systems for very cost-competitive NI cDAQ platform modules was easily accomplished with the NI DAQmx interface. DMC quickly transitioned our larger and more flexible BPT Low Voltage battery pack interface to a more basic one for control of all the required interfaces of a typical automotive battery pack: Vbat, IGN, GND, HVIL, CAN (see Figure 1). Similarly, DMC converted our larger and more complex ‘High Voltage Contactor Module” into the smaller and simpler sub-system shown in Figure 2. While the resulting hardware system would have easily fit into a smaller test system rack, the Client wanted to reserve room for future expansion and selected a 36U high test rack, as shown in Figure 3.
Software System
While the BPT hardware system was optimized for cost though selective hardware design, the software system of BPT was simply expanded to allow full control of the new low voltage and high voltage hardware sub-systems. As such, users of this more cost-effective BPT system still have full access to the rich BPT software feature set, and full testing capability, including:
- Test Execution Management.
- Test Sequence programming using NI TestStand (Figure 4).
- Automatic and Manual run modes (Figure 5).
- Control of DMC hardware modules using pre-configured TestStand Custom Steps.
- Easy to use NI XNET CAN interfaces.
- Automated and customizable Test Results Reporting.
- Optional Custom Overview and Data Display Screens (Figure 6).
- Optional System Link integration. (Figure 7).
- Optional MES and Server Integration.
- Optional interface for common PLC communication protocols.
Conclusion
This new BPT model perfectly fit the Client's battery pack test requirements, and their business needs: Providing maximum test value, with optimized capital spend, and room for future expansion.
Learn more about DMC's Battery Production Test (BPT) System and Custom Battery Pack and BMS Test Systems or contact us to discuss your next project.