Losing WiFi connection when unplugged?

[User007]

My Echo connects to Wifi fine and works when plugged into the mains via the USB cable. When I unplug the cable however it does not stay connected and loses all power - is this normal? It needs to be plugged in to work? I was under the impression it worked wirelessly and the USB cable was a charge cable?

[DParker]

My Echo connects to Wifi fine and works when plugged into the mains via the USB cable. When I unplug the cable however it does not stay connected and loses all power - is this normal? It needs to be plugged in to work? I was under the impression it worked wirelessly and the USB cable was a charge cable?

The Tap is battery-powered, but not the Echo or Dot.