I didn't add another fan. I just added another solar panel from one of those outdoor solar lights that you stick in the ground. Go to a cheap store and buy a solar light. Take the panel off the light and glue it to the outside of the housing of the 5 in 1, or if you have some extra hookup wire, mount it to your pole or somewhere near the unit, pointing it in the direction you have a problem with temperature spikes. In my case it was to the west, because my unit is in the shade when the sun is in the eastern sky. If your unit is in the sun early and late, point your panel to the north.
You will need to solder in your wires + and - to their appropriate position on the back of the existing single solar panel top. There are two blank spots on the back to join your panel in.
You will need to solder in your wires + and - to their appropriate position on the back of the existing single solar panel top. There are two blank spots on the back to join your panel in.