Development of experimental facility for testing battery thermal management system of electrical vehicles

Abstract

Electrical vehicles popularity is rising day by day because of their environment friendliness, lower operating and maintenance cost. A battery plays an important role in running electrical vehicles as they store energy during charging period and discharge energy at various rates as per requirement of electrical vehicle. While charging and discharging a battery, its temperature increase which adversely affect battery functioning. A battery thermal management system performs two main functions: regulate maximum and minimum temperature within battery pack and maintain temperature uniformity across battery pack. It should also allow the pack to work under a good range of climatic conditions and supply ventilation for hazardous gases generated inside battery pack. In present paper, a novel battery thermal management system is presented which is based on heat pipe and forced air cooling. This system is integrated with a battery pack of twelve 32650 Lithium Iron Phosphate cylindrical battery cells. Thermal gel is utilized as interface material between each cylindrical surface of battery cell and flat surface of heat pipe. Thermal gel will offer more contact area and reduce thermal resistance between battery cell and heat pipe. An experimental testing facility is developed to test battery thermal management system at various charging and discharging rates. The testing facility mainly include thermocouples, data logger and battery tester. K- Type thermocouples are installed at various critical locations inside battery pack and along with data logger they sense and store surface temperature of battery cells under various operating conditions. The battery tester is used to charge and discharge battery pack at various C-rates by varying voltage and current. By charging and discharging battery cell at various C-rates, we can simulate working condition of battery pack as it meet various electric vehicles demand like fast charging, acceleration, deceleration etc. The testing facility developed can be utilized for testing and comparing various battery packs designs.