Any suggestions on how to connect two different sized wire together?

We are installing an Air Breeze wind generator.

Sunny San Diego!
We have the mast up and have ordered 8 awg wires for the run to the batteries as they run is over 30’.
This conforms to the Air Breeze specs.
The wires coming from the Air Breeze look to be #10 or# 12.
I think the neutral and ground get connected together and then the natural and battery negative get run to the batter positive and battery negative.
We were thinking that putting a #10 eye solder less term end on the Air Breeze and then the same on the 3 8 awg cable. Then bolting the wires together. This does not seem ideal. They are running down an aluminum pole and will have about 8 “ of slack inside the pole so they could be against the side. We could put a hose over the connections and other insulation methods but again this seems less than ideal.
Some new eyes on this and any idea welcome!
Thanks,
Chip