In this work, we report a thermobattery that can efficiently harvest low-grade waste heat. The thermobattery utilizes temperature dependence of ferri/ferrocyanide (Fe(CN)(6)(3-)/Fe(CN)(6)(4-)) redox potential and employs the porous carbon textile electrode that is coated with single-walled carbon nanotube (SWNT). Simple and scalable dipping and drying process was applied to prepare the SWNT coated textile electrodes (SWNT-CT). The SWNT coating not only decreases the sheet conductance of the textile remarkably but also provides the number of available reaction sites for thermogalvanic conversion, resulting in improving electrical outputs. The capability for power generation in the thermobattery was quantitatively investigated by measuring potential versus current curves. Discharge behavior of the thermobattery was also discussed to provide an understanding of the internal resistances that limit output electrical power.