Rechargeable Li-ion batteries are dominating the present market due to their excellent storage characteristics and relatively lower maintenance. These features have also made them the most suitable choice for electric vehicle power supply. A thermal management system for Li-ion batteries is a crucial step to attain its maximum efficiency, better life-cycle, and most importantly safety. In this study, a novel cooling system is proposed and numerically simulated for 26650 cylindrical Li-ion battery cells by water flow through an axially inserted hollow pipe. It demonstrates a good outcome by maintaining the battery cell maximum temperature below 4.47 percent, 8.83 percent, 11.91 percent, and 13.7 percent for 1C, 2C, 3C, and 4C (charging/discharging) rates, respectively, due to high heat transfer through forced convection. This novel battery thermal management system can control the maximum temperature within the optimum temperature range for Li-ion batteries. It is also observed that introducing a 1mm radius pipe does not limit battery power much, and the minor changes in the inlet flow velocity within the laminar region have a very little influence on maximum temperature reduction. The study also finds that axial cooling results in voltage gain compared to traditional battery cells.