Before you add amp's read this.how to figure current draw of your system!

[wrx-killer- Sti eater]

a cap is not a battery, it never gonna do the job of a battery. Its a support device thats aids. I have a 20 farred cap on my escalade. You can here the diffrence with it and with out it, I running two battries , one hi-output 350 amp alt. But when I go spl with it next year- If I use this truck. Its going to have dual alt, and no caps. Caps don't work to well with spl events.

 

[skillz2k5]

I never once stated a cap was a battery, I compared the two as I did in the first comment I had made. The whole argument was cost effectiveness but it's still a compromise. You can get a slim line battery but it will always weigh more and be more bulky than a cap. You should expect to hear a difference when running a 20 farad cap if you have a big enough system... if you didn't you wasted your money and the time it took to install it/mount it. IMO batteries are more cost effective when it comes down to it, different installers will tell you different things.