You dont need an isolator. and use whatever gauge youre using in your car now. You could find what you need for prob around $25That wire is not cheap, what gauge are you using? Also I thought you needed an isolator?
Yes sir..That battery has a bad cell in it..That batt needs be replaced with a good AGM.Prob all you need at this point with the system you have in there, and be just fine.Deff get that replaced pretty soon.So I just let my car sit idle in driveway for 10 minutes with the stereo cranked up. The voltage from alternator stayed at 14.1 but my head unit is now reading 11.9. I think it's the battery.
Oh sorry thought I read in one of the post that you had a honda, maybe it was in someone's signature.Don't have a Honda it's a toyota camry