The EV does not mean the end of 12V automotive battery. For various safety reasons, complex modules are powered using two 13.5V / 200A batteries such that the Backup battery comes into play the moment the Main battery's voltage is outside operating voltage range.
The Ground Offset Test involves a voltage variation of +/- 1V on Supply Return line that may affect DUT circuitry referenced to an absolute 0V via remote ground. The diagram below shows how to use a combination of three power supplies to simulate the +/- 1V Ground Offset condition.
2022-06-29
Christian Rosu