Calibration of impedance measurement systems requires the definition of impedance standards that are stable and reproducible and that can be easily transferred (traveling standards). In particular, electrochemical impedance spectroscopy (EIS) is a technique that can be exploited in battery management systems (BMSs) in order to extract information on the internal state of a battery. Since the impedance of a battery is not stable and repeatable, the definition of a traveling standard matching the impedance of a real battery is an important tool in designing, implementing, and calibrating a BMS. In this work, we illustrate the actual implementation of an impedance emulator based on a microcontroller unit (MCU) that can be programed to reproduce the impedance of a real battery. The microcontroller is used as a finite-impulse-response (FIR) filter, whose frequency response is suitably programed to match the desired impedance. As a case study, the emulated standard is then used to calibrate a custom EIS measurement system, the whole procedure is presented in detail. It is also demonstrated that the impedance emulator can be used to calibrate standard commercial bench equipment for impedance measurement.