While your old cell phone may be obsolete or broken, the battery inside might still be as good as new. Although it's time for you to upgrade your service plan and toss out the old phone for a newer, sleeker model, be sure to take the battery from the back of the phone before you get rid of the phone.
Regardless of whether you plan to use your old cell phone battery again, you should never toss it in the trash. Pollution caused by discarded batteries can be detrimental to your health and to those around you. Batteries in landfills can leak acid and other harmful elements — such as lead — into the ground. In turn, these chemicals seep into groundwater and streams and can pollute the water you drink.
Rather than throwing your old cell phone batteries away, keep them. Many batteries still have life left inside them. And if not, any cell phone battery, no matter the type, can be recharged. While cell phones themselves require large amounts of power, hooking up your old cell phone battery to a lower-powered apparatus — such as a clock — will utilize the smaller amount of juice left inside the battery. While a universal battery adapter does not exist (as of 2010), you can convert the battery yourself. Solder two wires to the cell contact on your battery. Once this is done, you can charge and use your old battery. The battery can be charged using a number of different methods, including a self-made turbine or solar panel. A battery charger can also be purchased from your local hardware store. Your old cell phone battery can power any number of objects, including a flashlight, robot, clock or toy car.
If you don't have the time or the means to save and convert your old cell phone batteries, another option is to recycle them. Check your town or state's rules on battery recycling. Many places have regulations to help mandate the flow of batteries. Some private companies are also developing concepts to prevent the disposal and waste of batteries. For example, Energy Seed proposes the collection of used batteries — including cell phone batteries — to siphon off what remains inside the cells to power other objects, such as street lights.