It's totally worth it though dude. I had a high current amp in my last car (chitty audiobahn 2300hct) and stupidly I knew nothing about upgrading the electrical system. It was a 1998 Lincoln Mark 8. If you don't know, lincolns are almost completely electrical. I paid 4000$ for it, used, 6 months ago. Worked great for 5 months, no problems what so ever. I put this new system in, with the audiobahn 2300hct and within 1 month, so many electrical problems occured, I ended up having to trade the car in for 2000$, and it wasn't worth even that. The salesman was in such a rush to sell me a car he gave me 2000$ for a car that needed to go to the junkyard. If I woulda spent 800$ on upgrading my electrical system, I would still have my car, and another 4600$ (what the next car cost). Also, I think keeping the interstate battery as the main, and running the 2nd battery in the back would be better. It probably isn't needed for only the 1500 amp, but if you got both anyways, why not make sure you have the power for what you need. After my first stereo destroying my first car, I'm not taking any more chances. PS. I was an idiot and kept bumping my system as hard as I could, even though it was dimming lights to the point where it would almost shut my car off. Didn't realize I could cause permanent damage. Doh, expensive lesson learned.