With the growing adoption of lithium-ion batteries, the risk of battery thermal runaway is increasing, so effective temperature regulation for battery systems is essential. The air cooling system for battery thermal management offers advantages such as a simple structure and low cost, making it a promising solution for electric aircraft, electric vehicles, and other applications. In this work, the influence of inlet air velocity, inlet size, and inlet/outlet area ratio on the maximum temperature and maximum temperature difference in the battery pack was simulatively studied. When the inlet air velocity was 4 m/s, inlet size was 73 mm × 25 mm, and inlet/outlet area ratio was 1.25, the heat dissipation effect of battery pack was excellent, and the maximum temperature was 324.8 K. This research offers a crucial foundation for designing and setting the operational parameters of air cooling thermal management systems in lithium-ion battery packs.