Experts recommend replacing the batteries in your home’s smoke detectors at least once a year. But when you remove those old batteries, what are you supposed to do with them? How you answer that question could go a long way toward eliminating a deadly fire hazard in your home.

Disposing of old batteries isn’t always as simple as throwing them in the trash. EPA regulations govern how batteries should be recycled, as the heavy metals inside can leak out and damage the environment. However, batteries can also cause another potential hazard that should be taken into consideration.

Touching a battery’s positive and negative terminals to a conductor (i.e., metal) allows energy to flow out of the battery. This concept makes household items like flashlights function, but if the terminals are connected to an item with low resistance, the flow of current can cause a fire. To see this in action, watch how easy it is to start a fire in seconds with a 9-volt battery and a piece of steel wool.

Batteries can be especially dangerous when disposed of together. In one instance from April 2011, a man accidentally burned down his family’s home with nothing more than a few 9-volt batteries. He posted a video explaining how he had changed the batteries in his smoke detectors, placing the old batteries in a separate bag to recycle later. When the bag was moved, the batteries’ terminals contacted one another, causing the fire.

The best way to prevent this from happening in your home is to place a piece of electrical tape over the terminals of old batteries before you dispose of them. New batteries should be stored securely in their original packaging, not tossed loosely into a spare drawer or cabinet where they can contact one another or metal objects. If batteries must be stored loose, place a piece of electrical tape over the terminals until you are ready to use them. This simple step can save your home and save the lives of those around you by preventing a fire in an unexpected location like a garbage bag or junk drawer.

Safe Disposal and Recycling Options

Although most general purpose batteries (AAA, AA, C, D, 9V) no longer contain heavy metals and can be legally thrown in the trash (except in California), there are separate rules for car batteries, watch batteries, and some rechargeable batteries. This website explains what should be done with each type. If you do have batteries that must be recycled, this website will help you find recycling locations in your area.

[Nick Fox]