My car battery negative terminal bolt is so loose that it come off.
I failed to tighten it with a 10MM socket wrench.
Please note that I can tighten my car battery positive terminal bolt.
Please see the attached photos.
How to tighten the 10MM car battery negative terminal bolt?

 

A battery post shim may fix it, which are sold at auto parts stores.

Some people just stick something that is conductive metal in between the terminal; but, a shim made for the post is better.

 

Will this work?
https://www.canadiantire.ca/en/pdp/m...-0113601p.html

 

Yes, that should work. Those are the battery post shims I was referring to.

 

Thanks!