I bought one for the switch, but when I read the output, I discovered the power bank I was thinking of getting would've worked just fine despite being cheaper and at higher Mah rating. The one I have charges at 5v and 1.5 amps (the one designed for switch). Any power bank at 1.5 amps or above will work. It has to be at 5v. Please note this is for switch only and not the dock. The dock needs 16 volts and more amps.