http://www.carsound.com/UBB/ultimate...c;f=1;t=022965

Long read, but well worth it if you are considering buying a capacitor any time soon. Spells out in detail what they really do and dont do. They aren't the little miracle workers people tend to think they are

 

Take it from an electrical engineer(student)... for the most part caps are BS... if you're really having problems looking to a new altinator and battery. There's a thing in there that says something about stock engineering and other crap... they're really just trying to sell stuff. The only real use for a cap is to get rid of noise, and help even out the voltages, to a certain degree. And yeah, like their graphs show you need HUGE caps to really do much good if you're running any kind of power. I say, steer clear of caps unless you've already replaced your alt and battery, maybe added a second battery and you're looking for the little tweek to help even out your 10,000 watt competition stereo.

 

exactly!

Caps are good for one sole thing, filtering the DC voltage keeping your power clean.

 

Dont mean to steal the thread but as this situation relates to that seems my freind got screwed into that philosophy i also thought they were to help stop lights dimming and other things and the paople at the stereo shop sold em one till he found out they are for what you guys are talking about now my question is what would be best to do go with an optima or try to find a high amp slternator cuz my freinds lights dim to the beat of what ever hes listening to what is your advice to aleaviate that

 

Go with the battery first, it's the cheapest. It'll help but if it's still unacceptable get the alt. and maybe an aux battery in the trunk.

 

Why buy a tank, when you don't have enough to fill it?

Save the money you'd spend on a Optima or such battary and get an H.O. alternator. roughly the same price if you install it yourself. Don't forget to upgrade your big 3 wiring before you do any major upgrading.

 

Well to sum it up, the stock alt is no bigger than my fist and the stock battery is no bigger than my left butt cheek. So any of the 2 upgrades would help. Im runnin a hella efficient system so I dont have dimming problems. No speaker/ subwoofer in my car run under 93db so they dont need much power to 'woof' loud.

 

Well, it's not quite like that... the stock alt will keep the battery charged, the optama would release current faster than the stock battery when it's needed and charge up faster when your system isn't using the extra juice. The only problem would be if you were drawing massive amounts of current over and over and it didn't have enough time to charge up sufficiently, in which case the new alt would be handy. The battery alone will help. It'll help your car crank harder and everything too, it's a nice thing to have even if you don't have a system. Trust me, electrical engineer talking.

Oh and rem, me too. My JBL amps don't dim anything, even when they're PUMPED UP. They're all running 4 ohms though so I bet that helps.

 

Not really...

Dimming lights is a result of the voltage dropping from 14.4 to 12.2(roughly) It doesn't matter what battery you put in the car, the voltage will stop to 12.2, and you will still have dimming lights. Same concept as when you have a weak alternator and when you pull up to a red light and idle the lights will dim, but as soon as you rev it up the lights will brighten up. A bigger battery will allow you to do two things 1) abuse the alternator more without having to worry about the car starting next time, and 2) play with the car turned off. When the car is turned on the battery does nothing but charge up and act as a voltage buffer to your electrical components. And 4ohms is more harmful to a electrical system then 1ohm. ClassD 1ohm amps are superior in efficiency to A/AB. As an engineer you should know that 1ohm of resistance will be better then 4ohms.

My point is, if the car is turned on you should not use anything from the battery. That isn't its purpose. So if you are voltage dipping down into the battery, there is a much bigger problem at hand.

 

You should go read some books about Ohms Law and Kirchoff's Voltage and Current Laws then rethink everything you just said. I'm not here to start anything so I'll just leave it alone.

Oh, and read up on current/voltage sources.