Turned it one time too many.

[John T]

As others have said- crimp your own lugs on. I used this excellent quality Fastronix terminal set on my tractor- https://www.amazon.com/dp/B01LLWKXV6?th=1

View attachment 163600 View attachment 163601

I was going to suggest those.
I use them on almost everything. makes it easy to add additional terminals like your pic.

just search Mil-Spec. terminals.

 

[Pawnee]

I can't see if that's the negative or positive but if it's the positive then vice grips are going to be a bit risky.
I would cross drill it right through the battery post and put a nut and bolt through it.

 

[chim]

I use an anti-corrosion paste such as Penertox, NoAlox, CU/AL Aid or the likes when making connections on batteries, grounds, crimps on vehicles. The surfaces are always cleaned first. I coat the cables before stuffing them into the crimp lugs or splices. When bolting ground lugs to steel, I clean the metal to bare and coat it well.

It may be useful to some that the side terminal batteries are tapped 3/8-16. With my own DIY studs, nuts and washers it allowed adding the thick 2/0 lugs for my winch/jumper connections.