High Precision Test System for the Investigation of the Condition of Lithium-ion Batteries

Modern electric drive systems require more sophisticated monitoring and diagnosis methods for determining the expected life-time and reliability. Recently, continuous assessment of the electrical condition of electrical machines has become increasingly important. Investigations to predict battery life are of the utmost importance for Electric Vehicles (EVs). The evaluation of the instantaneous State-of-Health (SoH) of the battery cell packs requires a precise measurement system that encompasses the especially important specifications related to the operating conditions. In addition modern Battery Management Systems (BMS) rely on empirical battery models whose parametrization is crucial from the reliability's point of view. The model parameters are necessary to be indentified via the appropriate measurement data. To address these considerations, this paper presents a new test system for Li-ion batteries and control software based on LabView, which is capable of conducting high quality and completely automated battery cell measurements defined by user input test vectors and test suites. The test system allows conducting also real time condition monitoring in Li-ion batteries by discharge impulse responses. Finally several measurements on the experimental setup are performed. Analysis of the measured data validate that the designed device ensures high performance testing and post-processing.