it sounds like the alternator to me, basically your car is running 1-2 days cuz its running off the fresh battery, i had a brand new optima in my car had it idling for a while at a car show, and the car just cut out, i spoke to a friend of mine and he said that the issue is with the alternator, i have yet to get my car checked cuz something else happened, but i'm almost positive you'll need a new alternator, i would suggest uppin' it to a 200amp as well since you have an after market system. that's what i think, lol. please someone chime in with the correct answer. so i can fix my car too. hahaha.

 

Check the ground cable going from the battery. Clean the contacts!

 

I went to an autozone close by and they tested it in the car. Said the alternator was fine...should I upgrade the alternator to an higher output one? If so...where can I find one, how much and how many amps would be good?

 

Your std alternator should be enough for the job. The obvious thing for me is the power steering. Do you need to top it up? If so then suspect that alt is drenched in steering fluid. and on it's way out.

 

I replaced the battery again less than two days ago. Took the car out today and at a complete stop, the battery light came on and the car died. I was lucky to get it started right after (it barely started). Then I got the car home.

So, if I get the alternator changed, can you recommend where to get it, what kind, output, price for part and install, etc. I want to get this replaced during the weekend if possible. Thanks.

 

take ur car to autozone and have them run TWO (yes 2) alternator tests before finding a place to swap it out for you.

its not an overly complex job, you could do it yourself after ordering the parts from carson, but if you really arent up for it i recco either LMW in monrovia, or Dynamic Auto in what i think is Bolsa? talk to son.