Hoping to find a great use for your used batteries? There isn’t one. I only put this page here so you’ll know that used batteries are considered a hazardous material — like paint and nail polish remover — and are not intended to be thrown willy-nilly into the trash. If you live in Los Angeles, there are many hazardous material drop off sites which collect them. Other cities like Concord, Massachusetts limit their battery collection to “button” batteries, such as those found in hearing aids and watches, as well as rechargeable batteries. They don’t collect alkaline batteries (the ones identified by letter.) Check your local hazardous material instructions to find out what your city or town does.
Why should you care? Household batteries are filled with metals like copper, zinc, lead and mercury that can be bad news when disposed of poorly. The best you can do is avoid using batteries where you can, get rechargeable ones when you can’t, and dispose of all used batteries properly.