What size and type of wire does every one use?
 

What kind of wire are you using to connect EV battery banks together?

Are you using fine stranded highly flexible welding cable or thick stranded THHN type electric cable that holds it shape when you bend it?

After building several arc welding leads that consumed all of the fine stranded 1, 2 and 4 gauge wire I had amassed. I have started buying it from the scrap yard to have on hand for various power transmission projects.
I have rebuilt my collection of highly flexable fine stranded 2ga and 4ga "welding cable", collected a lots of THHN thick stranded 4, 2, 1, and 000 gauge used for residential commercial wiring.
The 000ga THHN was kind of an impulse buy, that is the shortest length of any wire gauge in my collection, only about 60 or 70 feet and not sure what I will use it on. I have the most 4ga THHN and 1 and 2ga fall some where in between.

I prefer the thin stand myself.