Go to hardware store. Purchase ONE FOOT LENGTH of copper tubing sized to fit your #6 wire. Yes it needs to be crimped and soldered.
Cut off a length suitable to make your own terminal.
In a VICE squeeze shut about a half inch of one end of the tubing.
FILE the inverter end to fit the terminal. Lots of side to side material removal. Copper is soft.
With a wire brush you bought at the hardware store, clean the INSIDE and outside of your new terminals, new copper penny bright.
Fit the tube end onto your cable, crimp then solder.
When soldering, apply it all over the copper tube terminal. All over. It's OK to use paste flux.
Apply appropriate heat shrink tubing to prevent lugs from touching each other.
Took longer to write this than it does to actually do it.
