Electric vehicles, with their numerous advantages, are a promising alternative to traditional vehicles. However, they are still plagued with high battery replacement costs due to short battery lifespan. As temperature is a key factor in this, battery cooling systems are widely explored solutions, but their associated costs remain to be considered. Hence, this study designs a cooling system for an electric vehicle battery considering the capital, operating, maintenance, and associated battery replacement costs of the system. The net present costs of two design choices, an active aircooled and passive PCM-cooled one, are minimized using a genetic algorithm, paired with a system simulation covering the electrical, thermal and aging behavior of the battery. Two cases are also explored – operation under a drive cycle and under discharge at 3C, representing routine and extreme use. It is determined that for routine use, having no cooling is still the most economical choice, and that for extreme use, PCM cooling is the most advantageous option, both in terms of temperature reduction and cost.