In a significant advancement for electric vehicle (EV) battery technology, German research organisation Fraunhofer has unveiled a breakthrough method for real-time monitoring of battery health. The innovation, developed by the Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), enhances a known technique called impedance spectroscopy and could revolutionise battery management systems across industries.
Traditionally, impedance spectroscopy — the most informative method for determining a battery’s state of charge (SoC) and state of health (SoH) — has been a time-consuming process, requiring the battery to be idle for up to 20 minutes. Fraunhofer IFAM’s new technique, dubbed “dynamic impedance spectroscopy”, eliminates that wait time by enabling real-time data collection even while the battery is operating.
The system works by overlaying a multi-frequency test signal on the battery’s charge or discharge current, capturing measurements up to one million times per second. These high-frequency data are then processed by algorithms that assess the evolving impedance values of individual cells, delivering detailed insights into internal conditions such as temperature, stress, and ageing.
“This method allows us to go far beyond just charge capacity and operating time. We can now obtain a complete picture of what’s happening inside the battery in real time,” said Hermann Pleteit, project leader at Fraunhofer IFAM.
Dynamic impedance spectroscopy is compatible with a wide range of battery chemistries, including lithium-ion, solid-state, sodium-ion, and lithium-sulphur batteries. The real-time monitoring feature could be especially valuable in applications where safety is critical — such as electric aviation, shipping, or grid-scale renewable energy storage.
Fraunhofer notes that by integrating this system into EV battery management, manufacturers can identify overheated cells during use and automatically isolate or limit them — eliminating reliance on slower, external temperature sensors. It also opens the possibility of dynamically adjusting charging strategies, balancing speed with long-term battery health.
“This technology paves the way for safer, longer-lasting batteries and broader adoption in demanding applications,” added Pleteit. “It’s a leap forward not just for EVs but for the entire battery-powered ecosystem.”
With industries increasingly focused on sustainable energy and electrification, Fraunhofer’s latest development stands to play a vital role in shaping safer, more efficient, and more intelligent battery systems globally.