Im installing a second amp into my trans am. Ive been told that at that after u surpass a certain amount of power its a good idea to have the system runs off an secondary battery instead of the main. If this true what type of battery what be a good fit?

 

try buying a better alternator first. the better your alternator, the faster, and more efficiently it charges your battery. or you could put a cap on your system?

 

Don't waste money on extra batteries or cap. The right way to go is to upgrade wire from the battery to alternator with atleast 4 guage or better, Upgrade the battery to body ground, and run the largest wire you need to the amp you are using. If thats not enough upgrade your alternator to 200 amp or better. I have installed thousands of systems and have never seen a cap to anything but put money into my pocket. The only benefit of a cap is that it will keep the initial spike from popping alternator. Extra battery is a waste also. If you alternator can charge one battery how is it going to feed two. Also you would have to use an isolator between the two batteries so they dont discharge each other over time. Only benefit of extra battery is yu could sit in a parking lot jamming for a longer period of time and still startyou car. I personally ran a Kicker 2500 (300 amps) from my stock electrical system for well over a year with no problems. Even light flash was minimal. Just don't run your system with the car off. Stock alternator is 140 amps so you should be fine ther for quite some time. I'm sure ther is some info I forgot but this is the high spots.