I've been having electrical issues from day one. Last year I had to replace my alternator and got a more powerful battery. Now my lights are starting to do the flickering to the beat. So I want to get a additional battery just for my system but I need to know where to begin. I have a 2005 Chevy Cobalt so the battery is in the trunk. I also have new 0 gauge power wire and ground wire I want to swap out. Any help?