1) Get two "4 D Battery Holders".
2) Wire these in series (black of pack 1 to red of pack 2) to produce 12 volts (8 x 1.5 volts per battery = 12v).
3) Wire the positive (red) of pack 1 to the center terminal of a "Size M Coaxial DC Power Plug".
4) Wire the negative (black) of pack 2 to the outer terminal of the power plug.
This will run the IQ for several long cooks. I got 6 long cooks out of mine before I stopped testing it. Use rechargeable D cells to save money.
Note that soldering is required to join the wires together and to the power plug. Use heat shrink or electrical tape over all electrical connections.