A remanufactured battery module includes a power assembly having a stack of battery cell assemblies. Each battery cell assembly includes a plurality of layers including a battery cell and a frame supporting the battery cell within the power assembly. The plurality of layers of at least one battery cell assembly includes an internal heat fin having first and second side portions extending beyond respective side edges of the battery cell and the frame. The remanufactured battery module also includes a side assembly in physical contact with the first side portion of the internal heat fin to enable the side assembly to act as a heat sink with respect to the first side portion of the internal heat fin. A layer of the plurality of layers of at least one battery cell assembly is new, and at least a portion of the side assembly is used.