Battery Impedance Measurement Using Electrochemical Impedance Spectroscopy Board

Battery internal impedance reflects the dynamic behavior in their continuous operation. Impedance measurement is an important issue in order to extend the battery run time, determine the parameter loss factors related to the thermal rise, and obtain more frequently updated parameters of the battery for better utilization. The battery online impedance measurement is also a crucial parameter to estimate the battery state of charge. The real time circuit has difficulties due to circuit complexity, implement at low cost and extract the low ranges ac ripple voltage response due to ac excitation. This paper proposed a simple way to extract the battery ac ripple contents using real time circuit topology for measuring the battery impedance. The compatibility and usability of different voltage measurement also investigated in this paper for measuring the low ranges battery ac ripple voltage. The analog filter circuit extracts the battery ac ripple voltage and current, the zero crossing and peak detector circuits detect the peak and zero crossing point respectively. The circuit simulation result shows that, the real time circuit based electrochemical impedance spectroscopy board can be designed at low cost and integrated into smart battery management system for assessing the internal characteristics of a battery regularly.