Like previously stated, I would not use the exact same approach if I were to do this again.

The 8mm PEX was so tight that I had to unwind and straigthen the wires. ( takes a lot of time )

I had to use silicone based oil ( plummer stuff ) in order to slide the cables thru.

Much of this hassle can be avoided by using a bit larger PEX like the 9.9mm / 10mm from Uponor or Roth.

( The downside to the larger PEX is that it will be difficult to bend. Especially around the junction box. You may need a smaller version! )


An easier but also a more expensive solution, is to use 16-core UV stabilized cable for outdoor use.

When deciding where to the attach the original cable in the junction box, you will want to put this offset to the side so you aim for the rubber grommit in the "charging tower". 

As for the cable strips goes you obviously want the good stuff like Panduit / Hellermann-Tyton / TR.