It was strange to me so I didn't really understand if device is powered with USB or with some internal battery.
Maybe you need to rephrase it or explain what that means exactly... if there is no battery why posting word Battery at all?
They should remove the word 'battery' to avoid further confusion since the device has no battery. The hardware wallet has a 5V USB input that matches the electricity supply of computer USB ports that is usually 5V as well.