Use the official charger that came with your device. This will guarantee that the charger will be safe to use with your device’s battery and is optimized to charge it as efficiently as possible. Most phones will have the battery port located at the bottom or side of the phone. Make sure you plug the wall outlet and the cord to a working outlet. Next, make sure that the female and male cable and phone connections match and plug the phone in. Charge to 100 percent and then unplug.