if i wanted to add an extra battery for my sound system stuff to run off of would i need a new alternator with a higher watt rating or just a capacitor?

 

all i have for my sound system is the capacitor...

 

Ok I might as well add my 2 cents and get 1 cent in change.

First Caps are band aids. Yes I used em in the past but there not helping your cars electronis.

Fisrt off you have to ask the question "Why do you want to add a extra battery?" Is there a reason. This is what should be done if your having electrical issues in the car ie. Dimming of dash and headlights.

1. Big Three
- Add 4 awg (at least) from the alt to the battery
- Add 4 awg (at least) from the Battery to the starter
- Add 4 awg (at least) from the ground of the battert to the Ground in the Chassis.

This will help in currect flow. The best thing you can do for a sound system. It also helps in bass hits if your into that.

2. Swap stock battery to a Yellow top deep cycle battery. These are great for sound systems and high curent flow.

Now if you still have a issue with current flow maybe look at the amp power wire you have. Is it a cheap sire that is brital? Might need to upgrade to a brand like street wires or Monster cable.

Now the cap. A Cap will help in keeping a steady 13 yes 13 volt to the system. Sometime there 12.5. My PG 1F cap is 13volt when charged. Caps are scary if they fail. I had one fail and it made a mess. Thank god it was not in the car.

If I am way off topic here let me know.