Electrochemical Impedance Spectroscopy Using a Charge Transfer Circuit

A battery system includes a first battery pack having a first positive terminal and a first negative terminal and having a second battery pack having a second positive terminal and a second negative terminal. The second negative terminal is coupled to the first negative terminal. A charge transfer circuit has first, second, and third circuit terminals. The first circuit terminal is coupled to the first positive terminal. The second circuit terminal is coupled to the second positive terminal. The third circuit terminal is coupled to first and second negative terminals.