Looking at my XC-90 battery to install fused pigtail and a "charge guard" unit to feed my 12V powered VHF/UHF radio. I see a tap off on the negative cable that I can put a lug on attached to a 10 Ga wire. On the positive side there are two red cables off of the battery. One larger than the other. The smaller of the two looks like it is fed through a fuseable link. I was going to put a lug on the smaller of the two and again go to 10 Ga wire. I noticed at the front of the battery there is a black plastic flap marked "+" under which is another post. What is the difference between this lug and the small red lug? I am inclined to hook up the negative like I described and hook the positive up to the lug under the plastic flap at the front of the battery. Again, both of my pigtails are fused with inline fuses. Am I going down the right path here or is there a better way to skin this cat?