If the fuses on your amps add up to 150, does that mean you need an alternator that puts out 150 amps? And what happens if you have an alternator that puts out less than the fuses on your amps?
your alt should exceed the number of amps you are capable of drawing. If it is the other way around then you are highly stressing your battery, alt, and all the rest of your cars electrical components at full draw. It also has a lot with teh way you have your system wired. if you have everything maxed out @ 1 ohm pushing peak power out of your amps then that is the case, but if you have a 1 ohm stable amp and are pushing it at 4 ohms it could be the difference between 30 amp draw at 4 ohms and 120amp draw @ 1ohm. (using a typical 1200watt mono block amp as a reference) how many watts are you running?
I'm planning to run 2 JL 10W7 which is 1000watts to 1.5 ohms. I do not have a amp just yet. I'm plannin on gettin either the JL 1000/1 or the Rockford Fosgate T1001BD. Both are using 100 amps and I'm also pushing my highes with a Kicker 350.2 which uses 50 amps.