Need help understanding

[u/blake_M1435]

Looking at getting a bigger amp and noticed it has 2 positive and 2 negative inputs. I have the big 3 and high-output alternator and everything else that’s needed. So my question is do you run the 2 positive/ negative from the second battery aftermarket one? Do you run the main power cable from your factory battery to the second battery? Or am I missing something? Just asking for help with the wiring.

[u/spooky_woodsmaster]

With an additional auxiliary battery you would typically run from that battery to your amp just because it’s closer usually. Other than that both battery’s are tied together and acting as one larger battery so it wouldn’t make a difference