Capacitor

when is a capacitor needed,how many watts is liek the limit before your battery starts to drain?

It depends on your alternator output.

Caps are never needed. Upgrade your electrical system an Big 3

If you are a ground pounder (SPL type), Manny is exactly right. If you are an SQ competitor, it helps with that last 5% - so it would be the LAST thing I would add to a system.

Unless you just think that it is cool to have a pointless usually round tube looking thing in your trunk. Then...I would buy a piece of cardboard and paint it and mount it in my trunk.

so pretty much another way to solve feeding all the energy is to upgrade ur electrical system and it depends on your alternator?

CAPS ARE USELESS.

let me find the tutorial i found on sound domain.

http://forum.sounddomain.com/forum/ultimatebb.cgi?ubb=get_topic;f=5;t=007801;p=

Yes lost of reading, but the 35 your going to spend on 1/0 wire, ring terminals, solder and a fuse holder/fuse will be worth it compared to 100-200 for a decent, i said decent cap.

the alternator supplies ALL the energy when the car is running - unless you are pulling so much power that the voltage sags to the battery float level (or lower), which is about 12.5 volts. Then the batteries will supply what power they can until the voltage sags below the cutoff point of the amp.
Adding another battery here will just be another load on the alternator and will not really help ..... you need to look at a bigger alternator if you're voltage is sagging below 12.5 volts or so.

When the car is off, of course the battery(ies) are supplying all the power. If you "burp" your system with the car off, and their are some good reasons to do that, then you will most likely need several batteries.

The big 3 upgrade can help deliver a little more power by lessening the resistance of the power and ground wires. It's a cheap and effective way of increasing the power output of your electrical system. Remember to use good connectors and crimp them tight. Most of the electrical loss is in the connectors.

so what would be the best way to keep your lights from dimming? ive upgraded my big 3 im about to get a yellow top will that take care of it? my alt is 120 amps i belive. stock 96 jeep grand cherokee.

so what would be the best way to keep your lights from dimming? ive upgraded my big 3 im about to get a yellow top will that take care of it? my alt is 120 amps i belive. stock 96 jeep grand cherokee.

It could...no way of telling bro. Untill you have hooked it up an see if it still dims, if it does, time for an alt upgrade.

I'm showing the stock alt. puts out 90 amps. There is an option for the 120 amp. May want to call a dealer 'n' see which you have. If your jeep has the 90 amp, that would explain the dimming lights.