In this paper, the characterization of textile-based thermoelectric generators made of carbon fibers (C) and nickel-coated carbon fibers (Ni) integrated into polyester fabrics is reported. We used carbon yarns inserted into a fabric. The nickel was then deposited by an electrochemical reaction (electroplating) in order to form a series connection of C-Ni thermocouples (105 pairs). The electroplating process was done in such a way that all the hot junctions of the thermocouple chain were on one side of the fabric and all the cold junctions on the other side. A temperature difference across the fabric, which happens in all wearable garments due to the body heat, will then generate a voltage which can be used to power small electronic devices. Here, two electrical characterizations of the thermopile i.e. Seebeck coefficient and internal resistance are presented. All these measurements have been carried out on the C-Ni thermocouple chain formed on carbon yarn in the structure of the polyester fabric. The coefficient turned out to be 1219 μV/K or 11.61 μV/K for a single junction.