48V battery testing and analysis for TLC applications

The purpose of this master thesis, in collaboration with Fiamm Energy Technology Spa, is to analyze and evaluate different 48V Lithium-ion batteries for telecom applications. Due to non-disclosure agreements between Fiamm and the different suppliers, the names of these producers cannot be shared so, in order to identify them, a number was assigned. In order to detect the best battery, the internal design and the electrical performances of each one were analyzed. For time constrains, only three batteries have been analyzed in details during the internship thesis. In the first part of the document the purpose of the project from the company point of view and a description of the lithium-ion battery technology are explained. After that, there is a description of the instruments utilized and an explanation of the various tests performed. The second part describes the teardown of three batteries and the results of the electrical tests. After that, a comparison between the different batteries was performed from design, electrical performances and software point of view, in order to determine the best one. The design comparison is based on the main design features of the batteries like the components of the BMS, the cable management and the cells arrangement. Instead, the electrical performances comparison takes into account the most critical characteristics like the capacity discharged, the maximum charge/discharge rate and the safety functions of the BMS. The comparisons mentioned above are based on the three batteries deeply analysed in this thesis and on others five analysed by Fiamm project team. Nowadays, supplier n.8 appears to be the best one. Fiamm has planned to evaluate other two batteries within the next months so the partial result obtained in this thesis could be different from the final one.