Lithium batteries are universally used in electric vehicles (EVs) and depend a great deal on the temperature of the battery. Thus, to support operations of EVs, it is necessary to provide an effective battery temperature control system. Battery Thermal Management System has the responsibility of maintaining the right temperature and temperature differential of lithium-ion battery pack for better performance, longer cycle, and safety. Public and industry realization of the need for high-performance and highly safe battery packs have led to the need to address thermal issues and cool the battery packs. The cooling plate design: The design includes a large number of mini channels and its function is to extract heat produced during battery operation. Despite the amount of work done on liquid cooling for prismatic cells, little work has been done for round and hollow cells (cylindrical cells). Furthermore, previous works on liquid cooling for cylindrical cells are limited with respect to flow rate, flow direction and number of channels studies. In this endeavour, aimed at establishing an understanding of the heat transfer characteristics of this micro channel cooling plate in a micro-electronics cooling application, a numerical computation employing computational fluid dynamics was performed on a micro channel cooling plate fabricated for a cylindrical Li-ion battery pack containing forty (40) cells. For purposes of studying flow velocity, Reynolds number effect on cell temperature and pressure distribution in the system when 3C and 4C discharge rate, a three dimensional model of the battery pack is analyzed numerically using computational fluid dynamics (CFD. According to the obtained results, it can be concluded that altering flow directions within the mini-channels enhances thermal characteristics. For instance, in each cooling plate, if the inlet and outlet of the mini-channel design are divaricated, it can decrease the temperature difference by 51 percent. 67% & 40. of NTDS and 31% for 4C when compared with unidirectional flow, 3C: 46% and 4C: 46%