In working up efficient test methods for traction batteries and their components the project team looked very closely at the specific aspects of safety at work and implemented concrete technical and structural measures in collaboration with fire safety experts.
A cyclical endurance test on a hybrid battery served as a pilot experiment for gaining experience with temperature control, current feed and time-critical monitoring of batteries with feedback to the charging generator. A thermo/vibration test bench with associated safety infrastructure and control elements was designed and the requirements for test equipment and safety infrastructure defined and planned. An existing EMC test site was upgraded to the new high-voltage requirements and test object specifications of large traction batteries.
In order to record the test object characteristics in a clear, comprehensive and reproducible manner, existing methodological descriptions in standards are often inadequate. Here, the project team devised new approaches for improvements and tapped into areas of potential to increase effectiveness. Based on preliminary experiments and in dialogue with vehicle and battery manufacturers, the necessary processes, actions and requirement specifications of test sites and safety systems were defined. Based on an accompanying hazards and risks analysis, the project team defined key tests, which were run on cells or modules and on safety systems. Indicative tests can thus be run at early stages of the product creation process and the scope of elaborate tests on the complete battery reduced. Special event rooms inclusive of the necessary infrastructure for controlling any fires or explosions that may occur were also planned and built. The existing methods for evaluating battery safety concepts were enhanced in a manner aligned to real-world operation using approaches from machine safety and taking into account ISO 26262. The battery testing centre created in Munich will continue to expand after the end of this development project in order to then largely cover vehicle and battery manufacturers’ testing needs.