Hi, this topic is a bit long ago, but perhaps still interesting.
Current from the fuse box to Hollen in my opinion is not a good idea.
The NV200 in Europe execution after about 20 minutes, the entire circuit is interrupted by switching off the engine.
It is better to pick up directly from the battery power, right behind it with eg Hedge 50 Amper and the power cord set into the car, then to the wall outlet, for example, again with 20 amperes or less Securing. Cable cross-section I advise you to take 6mm2 else comes back in the car hardly current.
Here meien outlets
The socket behind the seat
And the socket box for rear left in disguise
Gruß
Christian