You use whatever battery the system was designed for. If it's manual/etc says 24v, then you use a 24v battery system to power it. If it says 12v, you use a 12v system to power it.
There are a number of threads about (or mentioning) various minnkota systems, if it helps:
https://endless-sphere.com/forums/search.php?keywords=minnkota&terms=all&author=&sc=1&sf=all&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search