A:AnswerIt is a USB-A output. You can use the included USB-A to USB-C cable to charge but it is very slow compared to the normal cable I use to charge my phone (seems to be about 5 watts with the included cable, and 10 W with a generic USB-A to C cable I have next to my bed. More than enough power to top up your phone while playing music but fairly slow charging if you're wanting to charge a phone that's pretty drained.