Nano-hybrid materials based on a combination of polyoxometalate (POM) clusters and single-walled carbon nanotubes (SWNT) exhibit a great interesting application in molecular cluster batteries. The interactions between POM and SWNT and their detailed electronic properties have been investigated by employing first-principles calculations. Various models were constructed to study the geometries, interactions (binding sites and energies), and charge transfer behavior. Analysis of charge distributions reveals two different charge transfer characteristic depending on the type of POM interaction with SWNT. The simulation provides insight into the optimal structures in lieu of interfacial stability. Finally, the implications of these results for understanding the properties of molecular cluster batteries are discussed.