Here is a slick little case that safely carries 4 pieces of AA or AAA batteries. Plastic to insulate them so they don't short out and discharge, and snaps shut so they don't all scatter to the far corners of your bag, backpack, kitchen or desk drawer, etc.

Really handy for Photographers and other professionals who use a lot of batteries and also really handy for grouping your rechargeable batteries as you can simply label the protective battery holder case