Reference
Ladpli P., Kopsaftopoulos F.P., Nardari R., Chang F.-K., "
Battery charge and health state monitoring via ultrasonic-guided-wave-based methods using built-in piezoelectric transducers
,"
Smart Materials and Nondestructive Evaluation for Energy Systems III, part of SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, Portland, OR, USA, March 2017.