The keyboard came with a USB cable and a USB extension adapter for purposes of using this keyboard in USB mode as well as charging the built in battery. This cable plugs into the micro USB type B connector on the top edge of the keyboard. The other end can plug into a PC or any cell phone charger that has a USB type A connector on it. If you don't have the cable for whatever reason, you should be able to buy and use any micro USB cable off the shelf. Look for Android cell phone data/charging cables as a place to start shopping.