12V to 5V Usb hub

I did this usb hub to charge things in the back of my camper from a 12 volt battery, and also to have a monitor to see how many volt the battery has, so that I can know if it`s empty or full.

I used an old harddisk case for the box, since its stronger and also has a port that I could already use.
but in case you don`t have a case that fits, then i added also a printable case