For DC harness wiring ect.,, I exclusively pretty much use a variety of ''high strand count'' - oxygen free copper - ''silicone'' insulted stuff,, that's used ''a lot'' for quality R/C applications,, plus gold plated connectors.
Have been buying quality silicone insulated wiring off of places like Amazon lately,, that come in 6 multi colored ''4 meter'' rolls,, for around 15 bucks.
Pic is of the last 18g stuff I got.
It's made in chiner,, but is quality German spec.
I
View attachment 287213