Don't carry a spare battery in your pocket!

And it could also cause you injuries! Nice advice, it's good to keep in mind.

 

This seems blatant to me and if you're still going to carry it in your pocket, use a case. They're very cheap ($1) or you can use an empty pill bottle. It has to big enough to carry the batteries, of course.

 

That is also true, there aren't many accidents happening recently, most likely because people don't carry the batteries in their pockets haha.