If you're doing it to make it easier to disconnect the
motor, there's an easier way. I connected one once with an Anderson
plug. That's a heavy duty push on connector they use for
electric forklifts. Probably 10 times the amp capacity you need, and not expensive. But buss bars are a good idea too. You're only supposed to stack a max of 4 lugs on a battery post, with buss bars you can do as many as you need. A fuse would be optional but could be incorporated in the bar.