To charge an iPhone 5, connect a USB power adapter to a power source, plug one end of the charging cable into the USB adapter, and connect the other end to the charging port of the iPhone 5. Check whether a lightning bolt appears next to the battery icon.
If there is no direct power source, use a computer to charge the iPhone 5. Plug one end of the USB cable into the USB port of the computer, and then plug the other end into the charging port of the device. If the battery is extremely low, wait for at least 10 minutes before using the device while recharging.
Apple recommends using USB adapters that are Apple-certified.