Immersion Cooled Portable Battery Pack Concept for Small EVs

India is amid of a mobility revolution with the adaption of electric vehicles (EV). Such large-scale EV adoption comes with critical safety challenges related to thermal management of batteries. EVs catching fire during running & parked conditions has been widely noticed throughout the country. The cause of fire in most of the cases is poor thermal management and thermal mitigation strategies. Owing to this in Sep-2022, the Government of India amended the EV battery testing standards and implemented Amendment-3 of AIS-156 in a phased manner, with Phase-1 came into effect from Dec-2022 & Phase-2 from Mar-2023. This paper introduces a battery thermal technology that will address these automotive safety needs and government requirements by achieving better thermal management of EV batteries and reducing thermal failures. Present EV battery thermal management systems are either air (active & passive) or liquid-based cooling systems. Most liquid cooling technologies usually incorporate a radiator, pumps and cooling plate assembly, etc., which adds on to the weight, maintenance & finally cost. And are suited for 4-wheeler battery packs. Application of such liquid cooling systems is not recommended for the 2&3-wheeler or LCV segment. Further, Immersion cooling of electronics in data centers is a widely adopted and proven technology for efficient heat distribution. This technology can also be employed in EV batteries for direct cooling. And such temperature control will facilitate higher performance and longer life from batteries, along with meeting primary requirement of safe operations. In this study, immersion cooling is implemented in a portable type of EV battery. And the paper discusses the design considerations and results of the thermal 3D CFD simulations performed for worst case driving and ambient temperature scenarios for India.