Barbeque heat engine driving a generator-12V deep cycle battery-grill motor

John - I had the same first reaction. Then I read that Don indicated that he only wanted to run the fuel auger intermittently. So it's not a perpetual motion machine after all!  However, the conversion of heat directly to electricity is tough. DARPA has been sponsoring development of high density, high output (this is a relative term) Peltier effect device that responds to high levels of infrared heat and produces usable output (mA, vs. the micro or femto amps that you get from standard IR sensors, for example).  Can't buy anything like that yet.  Possibly a small closed cycle engine that uses some of the heat from the fire pit..... and can fit in a soup can and produce usable output current. Actually, this type of device might have significant commercial application if it could be developed. Not sure from the original post if Don has some kind of heat engine and is just looking for the DC generator.

Tom Hardy, PE
HVTA, Inc.
Allenstown, NH