First of all, you never NEED a fuse, unless of course you have a short. Are you going to have a short ? That would depend on a lot of things, mostly the quality of installation. If you feel even the slightest possibility of a short circuit happening, fuse it. I myself don't have a fuse inline my stand alone converter. The 0riginal 7345 was not fused either. None of my OEM battery cables are fused either, even the one going all the way to the generator. Many....if not most main battery cables are not fused from the factory,.....maybe because they figure the only way they can short, is in a catastrophic wreck ?? And that's good enuff for me.