I have an ecofan that sits on top of my woodstove. It is powered by the thermo reaction between 2 metals, thus exciting electrons which then power the fan. Great device for moving air around the cabin. Living off the grid in rural Alaska, I'm in search of a larger device that could produce 12 volts to charge the battery bank. The woodstove is in near constant operation for the winter months. Wondering if anyone has ideas how this could work, or seen a product out there?