SOC Estimation and Bubble Detection System Based on Ultrasonic for Lithium Batteries

In order to realize the portability and non-destructive detection of lithium battery, a SOC estimation and bubble detection system for lithium battery is designed based on the principle of ultrasonic characterization[1]. The system uses ultrasonic as a non-destructive testing (NDT) method for lithium batteries[2] and designs an ultrasonic transmitting and receiving circuit. The ultrasonic echo is filtered by Butterworth and Fourier transform and visually output by the host computer. Butterworth filtering and Fourier transform are performed on the ultrasonic echo through the upper computer, and the output is visualized. Nondestructive testing experiments were carried out on Ningde era lithium iron phosphate batteries and different types of polymer lithium batteries. The experimental data show that the system has good effects on SOC estimation and bubble detection of lithium batteries, and meets the requirements of portable, low-cost, expandable and nondestructive testing of lithium battery testing devices.