Dead alternator and a whole lotta unanswered questions

[redlineracer]

I had my alternator die yesterday and had my battery drained. I was on a rough road for a couple of minutes then I went to park. I had my accessories on for a minute then I turned everything off. When I tried to start my car, it wouldnt click over. I thought I had a loose terminal but it was not that. I had my friend jump me and it idled fine for a few seconds then I drove it home. I noticed that my car wasnt running right cause everytime I would barely touch the pedal it would like cut out and it shifted very hard. I also noticed that all my lights on my dash besides the CEL came on and were dim. I made it home and my car just dies. I checked my battery and it was completely drained of juice and its not one of those cheap Walmart batteries, Its an Orbital deep cycle battery from Napa. My dad jumped me a second time and I checked my alternator and it was dead also. I have an alternator ordered from Seattle and I am going to warranty the battery but I dont think this will solve my other questions. I have a twin halo headlight setup on my car and I dont know if this might be effecting my electrical issues. When I turn on my headlights, my car drops maybe like 50 rpms. They are on a relay system. Do I need a voltage stabilizer or some kind of electrical cap to "soften" the amount of juice coming from the battery? Cause to me it sounds like it is drawing ALOT of power from my battery. Also I have a have a 960 watt amp and some subs in the back and I had it bumping the past couple of days, could this also contribute to my alternator failure since I do not have a capacitor? I know the stock alternators are 70 amps. If I went up to a 140 amp alternator would this take care of my electrical issues? Thanks!

[Legacy777]

Replace the alternator & battery, and then see how the other things are.