500k reinforcement capacitor

Hello again,

Did Rockford Fosgate have it right in the mid 90's when they introduced the < size=2 face=Arial>< size=2 face=Arial>

RP7405 Reinforcement Capacitor .5 Farad??  And then something went terribly wrong?

I see these 5 farad- 20 farad- hybrid list goes on and on.  And the prices on these things??  absolutely rediculous.  A typical 20 volt .5 farad capacitor should cost $10 bucks,  but what are you paying for,  a LED Meter? ( I can make one of those) Decay resistant gold plating? ... hmm (how long is the car gonna last these days?)  and finally drum roll please...........A fancy evil skull-head face label descretely hiding the fact these are made in china for hmmm ........20 cents (maybe exagerated)

Bottom line-  Wasnt the idea to just condition the power source so the voltage down spike would decrease the tension on the cars battery/ alternator and the rest of the 12volt system?  With the technology today,  are we still forced to buy a $80 3.0 farad cap just to keep our alternator/ battery  safe from our 100 watt Punch?  Seems like an awful waste of resources.  My electonics skills are limited,  but isnt there a mathmatical/ engineering solution to achieve the same thing?  like a six pack of 90k 20 volt caps or somthing like that?  I look at these huge frankenstein caps at Fry's Electronics and stand there scratching my head.  Maybe im just not thinking big enough.  Fusion core- 1.21 gigawatt Mono @ 2ohms.  I know im new to this car audio stuff,  I could talk your ear off about audio frequency and sound design.  But im clueless when it comes to the 12volt phenomenum.

If anyone has a suggestion,  all i want to do is keep everything protected so I'm not buying a battery and alternator next fall.  Thanks,  in advance for not making fun of me.  Have a great weekend!

Be not guided by morality, but rather, integrity.

No, they had it totally wrong. These days with few exceptions it is nothing more than a money grabber and a bit of bling. Unless you have AGMs and systems well over 1kW output, forget them. If you have problems with dips on a particular load (eg, headlights) then they might be a suitable solution. As to protecting alternators - what a load of crap. Same too for batteries except as I indicated - high current surges on AGM batteries. Funny though how most reckon caps and batteries ADD stress and strain to alternators and batteries - which is completely wrong (they reduce such loading) - you must have read that from some old info source (LOL). I have said time & time again that a $10 1.2AH AGM will beat the crap out of 10F caps. I have yet to see anyone provide data or waveform images that suggest otherwise, though there has been heaps of rhetoric, and mention of ESR and charge times etc. Just follow normal recommendations - the big 3, don't discharge your battery too far, and don't buy crap alternators that can't handle jump starts or flat batteries.

caps are popular among 12v audio system owners because they make your system beat 10x harder and reduce strain on your alternator and battery so your car gains and extra 3HP...etc, etc, they are still around because people keep telling lies about how they are magical power creating devices, like a magic wand for a broken, usually poorly installed system. plus people will buy anything if it is chrome plated and has lights on it. i had to fight with somebody a few days ago because he was trying to say that a cap would have prevented the rca inputs to his amp from going out(vibration almost certainly killed them), i simply told him to unplug his battery and see how long his system runs on just that cap. he decided to close his mouth after that. as oldspark mentioned, they are only really good for one thing, helping a high powered system maintain voltage through short peaks in musical output, but as stated an extra battery in the right spot is much more effective. as long as your vehicles electrical system isnt poorly designed and your main battery and ground and alternator wires are upgraded to handle the extra current of your amps then you should be just fine.

Thank you for the sound advice. (no pun intended)  It brings confidence to this new project; I am definately on the right track.  I am certainly glad that all those years ago when I went to school for elecrtonics arn't a complete waste.  They are definately having me ask intelligent questions at a crutial step in the planning process.  I can now see how small details like: fixing a probem with another problem can end game with system failure.  Too much bling; [doh may be axepable in da' hood], can potentially sour a once solid design.  My next step now is to organize wiring on the amp rack to keep the audio (speaker/ interconnect) fair distance from the power/ remote/ ground wires.  Seems CAD is coming in usefull for a change. 

Thank you for all of the assistance,  till next post.

Myonus

May the force be with you...... in Newton's theory that is.

Be not guided by morality, but rather, integrity.

Oooo - I'm a luver of puns. A bit of electronics etc does help, but when not constantly involved, it's easy to get swayed by the hype. EG - caps have their pro's & cons, but for the most part, they are cons. The only valid use I have seen in BIG audio systems for caps is to protect AGM batteries, and that comes from people with experience. But that also fits in what I have often said, namely that AGMs can supply big Amps (as in Amperes) - ie, usually twice the short circuit current that an equivalent wet-cell can provide (because AGMs typically have half the internal resistance of a wet cell) - but AGMs do NOT like doing it. Hence caps to take the load off the AGM for short high-current bursts. The only other situation is where a (second etc) battery cannot be installed close to the amps (amplifiers). But even then, a 12V 1.2AH battery is smaller than a 1F cap... Many audio sites will also tell you that you get a higher PEAK SPL without caps. (That implies it might be higher still with wet cells rather than AGMs, but that might not be a valid conclusion.) If your system was 100W, then voltage dips should not be a problem. That's around 10A and is equivalent to high beams. The Fosgate P3001 is max 300W into 2 Ohms, hence about 30A input. Again, not much, and is probably be handled with most charging systems (alternators) unless lights and wipers are on etc. But it certainly requires good cabling etc. And ANY vehicle usually benefits from The Big 3 which should always be the first step for any performance electricals.     BTW - although Watts is strictly ONLY an RMS value, there are other "rubbish" terms like Music Power (Watts) and peak power etc. Traditional "Music Power" IMO is ok because that was simple twice the RMS value (no doubt a marketers adaptation of certain electrical formula to make amps sound... er, appear more powerful on paper), but peak power has no application. Peak power could vary anywhere from Music power to 10x the RMS power. The point being, you have to be careful what Watts they mean. Quality brands will only quote RMS because that is the only meaning for Watts, besides which it is the only meaningful application of Watts. That Fosgate rating however is in Watts RMS. They quote a "peak" of 900W - whatever that may mean - but that can be ignored. (How long for? Is it a thermal rating, or max peak current demand rating, or...?) But IMO you have come to the right place. I am audio-naive and more into the electrical and power side of things - eg, batteries etc. But there are some terrific audio experts here that give (IMO) outstanding advice. And others are gurus with alarms and remote start units etc. Note that most are professional installers. (But not me, I'm just a a pest - amateur in status but possibly professional by application LOL.) Anyhow, enjoy and welcome etc. Any problems - just ask. PS - I can like bling - especially in da'hoods etc, but I object when people think they have to have it. And if they can't afford it, and it adds minimal or no value anyhow... I'd rather spend that bling on an extra cider beer, or a charity etc.