Given the current global energy and environmental crises, researchers and industry professionals in the transportation sector are increasingly focused on replacing conventional internal combustion vehicles with electric and hybrid alternatives. Lithium-ion batteries, which are essential to these vehicles, are highly sensitive to operating temperature, and maintaining their temperature within an optimal range significantly influences performance. Designing efficient thermal management systems for lithium-ion batteries requires a thorough understanding of heat generation within the cells and accurate simulation of their thermal behavior under various operating conditions. This study aims to predict the surface temperature of a prismatic 8 Ah lithium-iron-phosphate battery under discharge rates of 3C, 5C, 7C, and 9C, and to compare these predictions with available experimental data. Two thermal models — distributed and lumped — were employed, using the Bernardi equation to estimate heat generation. Results indicated that applying the Bernardi equation in both models yielded acceptable approximations of the battery’s average surface temperature. Moreover, as the C-rate increased from 3C to 9C, the maximum relative error in the lumped model’s predictions rose from 1% to 5%. Among the C-rates tested, the distributed model performed better for C-rates below 9C. Overall, the lumped model consistently overestimated the average surface temperature compared to the distributed model.