A thermal battery includes a first conductive layer containing an anode material separated from a second conductive layer containing a cathode material by a separator layer containing a separator material; and a flexible pyrotechnic heat source, wherein the first conductive layer, the separator layer, and the second conductive layer are rolled together to form the spiral wound configuration. A method of manufacturing a thermal spiral wound battery includes preparing three slurries, each containing one of an anode material, a cathode material, and a separator material, depositing each of the materials from the slurries onto conductive substrates to form three layers, stacking the layers, and winding the layers together into a spiral wound configuration.