The battery application provides a set of unique test case setups. Test case setups include a test station, the associated cyclers, and one or more battery packs, modules, or cells.

Each test station requires a PXI-based process control unit (PCU) system. The PCU system can connect to multiple of the following components:

  • DUTs
  • Cycler sockets
  • Test chambers
  • Water conditioning units (chillers)
The battery application can complete the following actions:
  • Operate tests on each cycler socket independently while synchronizing the climate chamber conditions required by the different tests.
  • Connect each pack, module, or cell to its own DC cycler. If a DC cycler has multiple channels, you can connect each pack, module, or cell to its own channel.
  • Perform separate tests on each pack, module, or cell. Each test station must be configured for only one test type. For example, you might configure a test station for cells. At the test station, one cell can undergo a peak power test. Another cell at the test station can undergo a capacity test. The same is true for pack applications and module applications.
  • Perform different tests on one pack, module, or cell.
  • Generate more power by connecting DC cyclers in parallel. If DC cyclers have multiple channels, you can connect channels from different cyclers in parallel. You can also connect channels from a single DC cycler in parallel. Refer to Battery Back and Battery Module Test Station Configurations and Battery Cell Parallel Configuration Examples for more information.
  • Generate multiple cyclic, dynamic, and point measurements with the following possible frequencies in parallel:
    • 1 Hz
    • 10 Hz
    • 100 Hz, which is standard for battery cells
    • 200 Hz
    • 500 Hz
    • 1000 Hz, which is standard for battery packs and battery modules
  • Perform a thermal steady state according to ISO 12405-4 and DIN EN IEC 62660. Alternatively, you can parameterize a custom thermal steady state. Refer to Thermal Steady State (STMC) for more information.
  • Trace drive cycles in the form of measurement files. Use measurement files with EDAS32, DIAdem, MATLAB, MDF4, CSV, or PAtools binary.
  • Trace drive cycles in the form of PAtools step tables.

Battery Pack Applications and Module Applications

The performance of a PXI controller governs the test station setup. You can connect two climate chambers to one PXI controller. One PXI controller can test up to four DUTs at a frequency of up to 1000 Hz. The power connector of each DUT requires at least one cycler channel. To increase the power on a DUT connector, link the cyclers in parallel with the cycler model capabilities.

With the battery pack and module applications, the following configurations are possible.
Table 3. Configurations for Battery Pack Applications and Module Applications
Application Type Number of Power Connectors per DUT Number of Parallel Cyclers per Connector Number of DUTs in the Climate Chamber

Pack, Module

1

1

1 to 4

Pack, Module

1

2

1 to 2

Pack, Module

1

4

1

Pack

2

1

1 to 2

Pack

2

2

1 to 2

Pack

3

1

1

Pack

4

1

1

Battery Cell Application

The performance of a PXI controller governs the test station setup. One PXI controller can control up to 24 DUTs at a frequency of 100 Hz. To increase the power on a DUT, connect the cyclers in parallel with the cycler model capabilities.

Each parallel connection reduces the number of simultaneous cell tests by one cell. For example, if two DC cyclers are connected in parallel, it is possible to test 23 cells simultaneously instead of 24.

Setpoint Control of the Climate Chamber

Test stations that test two or more DUTs in a single climate chamber require controlled access to the climate chamber. The test stations require control of temperature setpoint values and humidity setpoint values.

Communication with the climate chamber takes place from the main test if you are testing cells. Communication with the climate chamber takes place from the control test if you are testing modules or packs. The main or control test must include the respective driver for the climate chamber.

The battery application uses a primary and secondary relationship to indicate the level of control a test has in relation to the chamber setpoint values.

  • A primary test has primary control of the climate chamber temperature and, if applicable, relative humidity setpoints.
  • All other tests are secondary tests.

When a primary test no longer requires control of the setpoints, one of the secondary tests becomes the primary test. A chamber priority queue manages the test order for the chamber setpoint control.

The following steps describe how the battery application controls temperature setpoints and humidity setpoints.

  1. The first test that requests chamber setpoints becomes the primary test.
    1. The battery application sets the chamber to the requested setpoints.
    2. The test is added to the beginning of the chamber priority queue.
    3. The test may continue test execution.
  2. Secondary tests are added to the chamber priority queue depending on the order that the secondary tests request the climate chamber.
    • A secondary test that requests the same setpoints as the primary test can continue test execution.
    • A secondary test that requests different setpoints than the primary test must wait to continue test execution.
  3. When a test no longer needs the chamber set to the current setpoints, one of the following results occurs:
    • The test requests new setpoints.
      • A primary test waits until the secondary tests do not require the previous setpoint. Then, the control test or the main test accepts the new setpoint.
      • A secondary test waits until the primary test requests the same new setpoint. Alternatively, a secondary test becomes the primary test.
    • The test releases its setpoint request. In this case, the test is removed from the chamber priority queue.
  4. When all tests are finished using the current chamber setpoints, the first test in the chamber priority queue becomes the primary test.
    1. The battery application sets the chamber to the requested setpoints of the new primary test.
    2. The tests waiting on the new setpoints can continue test execution.

This process continues until all tests are complete.

The following figure shows how the system controls temperature when two tests request the same temperature.
Figure 3. Temperature Control When Two Tests Request the Same Temperature
The following figure shows how the system controls temperature when two tests request different temperatures.
Figure 4. Temperature Control When Two Tests Request Different Temperatures
The following figure shows how the system controls temperature when a test requests a series of temperatures.
Figure 5. Temperature Control When a Test Requests a Series of Temperatures