Since these wires are meant for Datatransfer i think that they wont work…
I didnt find any pictures but this is how a usb looks like: (not exactly but you get the point)
(ROSA = WHITE)
I think that you would have to take the power wires and not the data wires…
The Datawires probably wont offer a constant energy flow like the power wires…
To your Question:
It will probably safe but i think it wont work.
I hope you understood my chain of thought