A modular thermal management system for a battery in an electric vehicle is provided. In one embodiment, a modular thermal management system for a battery in an electric vehicle is provided. The modular system includes a plurality of manifold segments. Each of the manifold segments further comprises a plurality of fluid ports adapted to connect to a heat exchanger fin for a battery cell. Each manifold segment corresponds to a battery stack comprised of a plurality cells and heat exchanger fins. At least one manifold clip is provided for securing two adjacent manifold segments together. The manifold clip bridges the coupling joint and engages retention features on each of the two manifold segments in order to inhibiting separation longitudinally between the two manifold segments. A plurality of manifold clips are configured to secure a plurality of manifold segments together accommodate a plurality of battery stack configurations.