Wiring in my new converter?

[The Newell]

Hi guys,

I am wiriing in my new Intelli-Power converter into the Newell that has. Just wondering about the wiring. I understand that I need to run a positive and negative wire to the battery and to the fuse box. Right now I only have a positive and negative wire going from the battery to the fuse box. Do I need to leave these pos and neg cables from the battery to the fuse box so that I can have my 12V when I am not hooked to 120V (going through the converter)? Or is there another way to insure I have 12v power when I am boondocking and away from hook ups?

Thanks,

Joseph