As useful as a cell phone is, it's practically a paperweight if it doesn't have a functioning charger to power it. Cell phone chargers are accessories that many technology users feel you can't have too many of, whether you like to have extra chargers around to power up at home and the office, or just to have a backup on hand. With an existing demand for extra chargers, it can sometimes be possible to sell a used charger without the phone that it came with.
Figure out how many phones your charger can be used for besides the unit you got it with. You can do this by browsing some sites that sell replacement chargers, looking up yours by the model of your phone and reading the listing to see what other phones this charger is compatible with. Be sure to check a few sites to be sure (you can start with places like cellphoneshop.net, wirelessemporium.com, and accessorygeeks.com, as well your phone company's official site).
Check to see what your charger is selling for new. Find replacement chargers like yours for sale new (check the same websites mentioned in Step 1), and use this information to price yours accordingly. A price that is somewhere between 50 and 75 percent of retail (or less) will probably be a good discount for a used charger in good condition.
Lump your charger with other phone-accessory items you're trying to sell, if possible. Cell phone chargers are not a terribly valuable or expensive item, so you'll have the best luck if you can sell it with a phone (even if you're selling it as an extra) or with another package of related accessories for the same type of phone.
Create an ad. If you intend to connect directly with a buyer (which will probably ensure the best value), create an ad for print or electronic submission. Be sure to include a photo of you charger (since someone looking for a replacement is likely to recognize what they want instantly) and information about what phones it's compatible with.
Sell locally in person. Post printed ads in around town advertising that your charger is for sale. Place the ads on community boards, paying special attention to areas where likely buyers are going to see them. College campuses are a good place to find tech-savvy people in need of a bargain, while coffee shops are generally a likely place to find electronics users. Look especially for any restaurants or cafes that have bulletin boards and are located close to an electronics or cell phone store.
Sell online. In addition to any attempts to sell on online classified ads or auction sites, check out websites that purchase used electronics, such as sellmymobile.net, sellmyelectronics.com, and buymytronics.com.