Life cycles test on a lithium battery system

The topic of the paper is the life cycles test on a lithium battery system 288 V-40 Ah, 11,5 kWh. The test procedure tries to simulate the typical utilization of an electric vehicle: the batteries are discharged by means of a typical profile in urban and suburban context and charged by means of traditional charges and fast charges alternatively. In this way it is possible to simulate the utilization of a driver who uses the electric vehicle and charges the batteries at home (traditional charge) or at a public charging point (quick charge). These tests permit to identify and understand possible problems of the storage system under quick charge and discharge cycles, as well as to define how the performances decrease during the operation. The paper shows the details of the battery system under test, the complete test procedure and the results in terms of reduction of the global performances (life determination as number of cycles) and behavior of the single cells (unbalancing).