So, did anyone find a solution. I was about to buy it, but then when I look at the documentation for the power supply voltage I cannot find it! Documentation is quite poor I must add.

I do not need battery operated solution, and the USB power is super ugly and inconvenient!

I need to use external 5V power supply connected to pins inside the board in a professional manner (no pcb hacking). Is this not possible? I cannot believe it!!