i think you might have misunderstood me I do not recommend a dual setup as it is totally unnecessary as he only has one amp and is not going to go to competition or run his system with the car off for long periods of time. I recommend the red top battery if he has to get a battery and being his stock one is old the red top would be a good upgrade. Dual is ofcourse better but more expensive and not needed for his type of usage.
I recommend a circuit breaker as i use one that is 80amp or 100amp i believe but see what the rating is on your amp is probably has 2 30 amp fuses so find out what your total amp is for your amp and maybe get one at that size or slightly larger. I got larger as i knew i was going to add a second amp to run my components in the door and wanted to make sure i get a circuit breaker large enough to handle both amps. also i recommend a 4 agu battery running to the back so you dont have to upgrade in the future or even 2 gauge if you can afford it but it might be an overkill.
Originally Posted by ppro
Write down what you plan to do, and the order in which to do it.
faiz23 has the right idea, in terms of the order to do things, but his solution (which I would recommend) involves two batteries and therefore more complex wiring and a dual battery system solution. If just buying the Optima battery leaves you low on $$ then the dual-battery solution is way out of reach for now.
Make sure you put a right-sized circuit breaker between the battery and the lead going to your high-power components. An 8 gauge wire and 30-40 amp breaker should be a good starting point. Remember, even if the fuse in the amp blows, if the wire from the battery to the amp shorts on something, and you have no breaker between it and the battery, your car is going to burn to the ground.
If you have an HID system already paid for, do that and see what happens. Then do the "big three" next - it's cheap and if you take the time to look up the wiring in the factory manual and trace them down in the car, should be reasonably easy.
Then see where you stand. If that's still not enough, look at the Optima. Problem is, the terminals or poles might be wrong and you will have to deal with that. More $$.
Go see the Optima web site and call them.
Optima recommend a Yellow Top battery for the sound system side of a two battery solution and they're right. Just read the web site. And don't let anyone tell you it's marketing B.S.
If you're still having troubles trying to understand and figure out how to do this, you probably should let someone who does it for a living at least help you. There's a number of things that you can do that will not come out well if you make a mistake.