EXPERIMENTAL STUDY AND NUMERICAL SIMULATION OF BATTERY ARRAY WITH PARALLEL CONNECTION

• Main Author: Sya'banur Rozaq, M.
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/74267
• Institution: Institut Teknologi Bandung

Lithium-ion (Li-ion) battery are undoubtedly the most promising energy storage for electric vehicles battery pack due to its high-power density and long cycle life. Generally, a battery pack installed in electric vehicles consists of several identical Li-ion batteries connected in parallel to increase the capacity so the vehicle can travel further. This study aims to observe the effect of the uneven current distribution and the current rate variations against the temperature distribution and temperature rise in the parallel-connected battery array. This study limits the battery array by using 3 batteries connected in parallel, which underwent a discharge and charge process at current rates of 1C and 0.5C. The experiment is conducted to discover the electrical characteristics and measure the temperature of each battery. The simulation of the battery array is also implemented by using a model that has been validated in previous study. The experiment results show that the parallel-connected battery array experiences an uneven current distribution which causes an inhomogeneous temperature distribution. During the discharge process, the current difference between the batteries gradually decreases until it instantaneously reaches the same value. The current from the battery with the highest temperature decreases further and increases sharply for the battery with the lowest temperature afterward. Thus, the current difference increases once more. The current difference between the batteries at the end of the discharge is higher as the current increases. During the charging process, the current difference between the batteries steadily decreases until it is similar when it reaches a particular SOC and fluctuates toward the end of the charging process. The battery experiences an increase in temperature as the charge and discharge process continues, and the maximum temperature is always experienced by the end of the process. The results showed that the non-uniformity of temperature distribution and the highest temperature increases as the current rate increases. The simulation results successfully represent the battery array temperature rise. However, a drastic increase in temperature occurs on the surface of the batteries, which face each other.