MADN00BIE

It's a 03 4x4 Mitsubishi montero frame runs from front to back and I did drill a hole in the back and ground to the (frame.) The added battery in the front also drops down under and grounds to the (same frame.)

Guys all 4 batteries are grounded to the frame. But the audio shop guy told me it was wrong last time (each battery grounded to frame) and had me buy more wire and ran a ground so that all 3 batteries at the time had a ground running from each battery to each battery. He said "if you didn't do it that way you would not complete the ground loop and it wouldn't charge right" So I guess I should have asked is this statement true in anyway? Is it okay to just ground each one to frame.

Guys all 4 batteries are grounded to the frame. But the audio shop guy told me it was wrong last time (each battery grounded to frame) and had me buy more wire and ran a ground so that all 3 batteries at the time had a ground running from each battery to each battery. He said "if you didn't do it that way you would not complete the ground loop and it wouldn't charge right" So I guess I should have asked is this statement true in anyway? Is it okay to just ground each one to frame.

In my last car the guy at the audio store said "You have to have a ground or it will not charge right" I just wanted to know how bad I would suffer charge wise not running one. Edit: He said I need "ALL the grounds connected or it wouldn't charge right"

Okay, I have hit a big issue! I ran a 0 gauge power wire from my front Battery to my new back batteries (XS D3100) and I have no way to run a ground wire. My suv is fully loaded. I have no more room.. I have looked at every side. Top, left, right it's all full of factory wire running already. It was all I could do to get the power wire run. The only way to run a ground wire is going to be right over the top of the carpet. How bad will I suffer to just ground to the frame in the back? This is my setup right now..