battery isolator

im hooking up my system this week. i got about 7000 total watts. i added a second battery in the trunk and i was wondering what kind/brand/size isolator i should get?

That depends on a lot of information that you have not given. What kind of vehicle? How many amps is your alternator? What is the exact make and model of both of your Batteries? How long do you expect to play your system with the engine off? Is that a consideration? What type of power supplies do your amps have? What are their exact makes and models? What are the make, model, and quantity of subs that you are using? What type of enclosure are you using? If you have some or all of this information I have solid answers for you.

Fine lets say those amps can do 7 KW. 1000W @ 50% = 160 Amps per amp 7 amplifiers X 160A each =   1120 Amps 1/0 AWG @ 350A = X4 1/0 AWG power cables X3 Kinetik HT-2400 Batteries You will need X2 240 amp Alternators. 240 Amp Isolators are about the largest I've seen. You would be better off using 300 amp contactors.