Rapid impedance measurements for 50-V battery modules

The shift over time of the internal impedance spectrum of a battery has been shown to be a useful diagnostic tool for determining the health of the battery. The Idaho National Laboratory, in collaboration with Montana Tech of the University of Montana has developed techniques that enable rapid in-situ measurement of the internal impedance spectrum of a battery for onboard applications. Previous hardware to implement these techniques were limited in performance, (underestimation of the imaginary response) and only capable of measuring batteries up to 12V. The hardware has been upgraded to improve performance as compared to previous hardware versions and to accommodate 50V module-level battery systems. Upgrades included increased noise suppression as well as increased power distribution and dissipation. Because of the increase to a 50V system additional protection was implemented to provide protection to the hardware. In addition the hardware was designed as a modular system to help with testing and development.;Once completed and tested the hardware showed significant improvement in performance and was no longer under estimating the imaginary response of a battery. In addition to the improved performance the hardware was fully capable of making rapid in-situ impedance measurements on batteries of 50V. Implemented protection proved to be successful in preventing damage to the hardware while the modular design helped to reduce development time and increase the flexibility of the hardware system.