Debate, Stiffening Capacitors

I recently have been answering peoples' questions regarding car audio at Yahoo!Answers. There is a gentleman there who claims capacitors work. He claims he got a 4 volt increase in his system upon adding crapacitors. We have been debating back and forth whether they work or not.

I keep telling this guy, who happens to be the 'top contributor' for answering q's about car audio, that he needs to go to the12volt.com and search posts about caps' usefullness, or lack thereof. He tells me that noone here knows what they are talking about regarding caps.

Anyways, i've been searching the12volt.com for a good link that explains how they don't work, but with no luck. I've seen them before but can't find them now. Can someone give me a site address that explains, in Great detail preferably, the uselessness of caps?

Much Love to the real Car Audio Gurus here at the12volt.com. Thanks.

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

Pretty good thread on CapsThis one was the best I could find without sifting through all pages.There are tons of info on these on this site, the link i posted was on page 2 on a search for "capacitors"
GL

sS

-------------
RTFM

I always get confused on this as well because you hear so many different things and theories from everybody. On here, caps are useless, spend money on higher output alt, which makes sense to me, one dealer says no to caps or alt, but go with *x* brand battery or multiple batteries, another dealer says no to alt, but use caps and batteries, enough to drive a person insane!! Wouldn't all vary based on the systems power needs and/or how the person uses the system?

The dealer evidently gets incentives to sell those expensive batteries. Most don't realize that they only store power and in turn, requires more alt.

Oh, yeah, this stubborn guy also says batteries "create power from chemical reations". He swears that batteries create power! Moron.

Thanks, spookiestylez.

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

I can't explain it as good as some of us on here,but if you have a problem with your headlights dimming, adding a cap isn't going to do anything to solve your problem.The only thing its going to do is add more of a strain on your charging system because now it has to charge the cap as well.Basically caps are a $80+ band aid, when the proper thing to do would be to have your battery and alternator checked out, most places do it for free.Then do a more proper upgrade like getting a higher output alternator that will keep your electrical system charged,getting a better battery (just cause),and if you really feel froggy upgrade the big 3.Which would be upgrading the 3 main cables in your vehicle.The cable from the battery to the alternator,from the ground on the battery to the chassis, and from the engine to the chassis.Either adding to or replacing to the factory cables,using the same if not a larger gauge.
Hopefully i put enough information out there for someone to fill in the blanks, and there is a sticky on the big 3 upgrade on the main page


sS

-------------
RTFM

No, thats not The link i was looking for. I was refering to the one in which there are a million different math equations about ESR, etc... But thanks spookiestylez, for the quick reply.

Anyone know where i can find what i'm looking for? I've seen one of the 'big dogs' here at the12volt.com refer to it once or twice before.

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

Here is the best information you can give him

he can even try the experiments for himself

Well this is funny because I was in a debate with the exact same person in question. I posted the same information that aznboi posted an got the response "the math is right but dosen't work that way in the real world, I have checked this on a o-scope and seen the results for myself" was what he said. I say stay away from Yahoo answers, people don't listen there.

Don't you think caps are useful to someone who just put in some $300 amp and sub package and notices the lights dim a little. So wouldn't it be better for him to purchase that $80 cap or purchase a couple hundred dollar alt plus installation.

aznboi3644 wrote:

---

Here is the best information you can give him

he can even try the experiments for himself

---

Great link!!I learned something new for the day!



-------------
RTFM

Thanks, aznboi3644! If his eyes are still closed after this, I give up.

Much love.

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

jmelton, can you send me a link to that yahoo forum? I'd be intersted in seeing it. Sounds like some yahoo thinks he knows what he's talking about! ROFL I'll try to set him straight.

Oh, and for the record, batteries DO create power using chemical reactions, but they cannot do it forever, thus the need for an alternator. The primary purpose of a battery in a car is for starting the car, nothing else. While they CAN provide instantaneous burps of power for use by accessories, the alternator is the primary source of ALL power in a car.

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Sure haemphyst. Um, just type in 'yahoo answers' in a search engine. Go to 'cars and transportation' at the left of the screen. Go to 'car audio'. Its pretty easy from there. His screen name is sparky3489. BTW, what's your yahoo ID so I can 'look-out' for ya? Mine is jmelton86 there as well.

Or,     https://answers.yahoo.com/dir/;_ylt=AITFyXmaSVc8DfhIYizB11dOxgt.?link=list&sid=396545177

Pieces.

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

The only good use for a capacitor that I have ever found is with the 1400watt Kinetic that I used for SPL burps. That is the total extent of it's use; asnd even then it was only good for very short term stiffening! That's it.

-------------
David Fancher
USACi World Finals 2006
4th Place SQ PRO 601+

For a 2 second tone in my vehicle, here are the results I found last summer in testing

Before I go into my testing, DO NOT TRY THIS!   The voltages and impedance loads I use are not safe for daily driving

(6) Kicker ZX1500.1's
(6) Kicker S10L7D2's
(8) The "V" 16/12 volt hybrid batteries

The amps I have are rated at 750X1@4 1500X1@2 both at 14.4 volts

MY batteries under a full charge and rest sit at 17.94 volts

My nominal impedance of each woofer is 1 ohm, the actual impedance is actually .93, and the impedance with box rise is 1.51 ohm at 63 HZ


So now let do some math with ohms law

Amps were measured via 2 meters to read 68 volts and 48 amps on the output side of the amp, roughly 3300 watts

So we know watts (3300) we know voltage at start (17.94) where does that get us?

3300/17.94= 183.94Amps    Guess what I measured on the power leads of my amps?    over 220 amps of curent draw!

Lets try again another way

Ve know voltage is 68 volts coming out of the amp and resistance .9 at rest, 1.5 SO

68 x 68 / 1.5 = 3082      68 x 68 / .9 = 5137    figure the average 5137 + 3082 / 2 = 4109    4109 x .8   (for 80% eff.) = 3287....wow right again



Ohms law is ohms law, with the power draw I have with 8 batteries.   I can play my system for only 2 seconds without my betteries losing resting voltage, I typically can burpo it once for 2 seconds and let it sit and the batteries will re settle where they were.   But once I do that again, they will typically set at 17.2-17.4

Each battery I use has 120 amp/hour rating, and also has a 1800 amp burst discharge rating

I know there are not any Cap's out there that could magically fix this power draw situation!

-------------
2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place

screenname: ddmcp2000 (preferred, thank you) and/or haemphyst

I couldn't even read some of that stuff... I gave up! That is one of the biggest garbage forums I have ever had the misopportunity to trip across..

Unsee! Unsee!

;)

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

kassdog wrote:

---

Don't you think caps are useful to someone who just put in some $300 amp and sub package and notices the lights dim a little. So wouldn't it be better for him to purchase that $80 cap or purchase a couple hundred dollar alt plus installation.

---

No - the cap will not fix the "dimming lights" syndrome. Caps only tax the charging system further - as has been mentioned. Make sure the existing Alt & Batt are OK. Make sure the system is wired with the correct gauge cabling. Make sure the ground is solid. Do "The Big Three". Get a better battery & alternator. That's the correct sequence to follow.

-------------

So I sent the guy that wonderful link aznboi3644 put up. He replies with;

"While the article that you site holds tru, there are a few errors that time has altered. This article was written some time ago and changes in the manufacturing of capacitors. In the article an ESR of .017 was given, the problem is that caps made today have an ESR of .0016 or less which is a far cry from days of old.

What does this mean? It means the calculations and information now change quite substantially and can no longer be held as true.

Re-read the article and re-do the calculation with the new information and you wil see that the benifits of a cap can no longer be marked as useless."

Is this legitimate?

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

My only comment on this is, of all the local shops I have ever ventured into, and of all the systems they have done for customers or for themselves, I never hear or see of an alt upgrade, its always multiple batteries and/or caps. And I never understand it because lets face it, the owners and installers always have some multiple thousand watt system that they sink thousands and thousands of dollars into, why don't they spend several hundred more on a high output alt if that is what is needed? Are all of them just stupid to this? This is why I get so confused on the issue. One other thought with todays vehicles that I'm curious about, if you wanted to change the alt to a bigger one, how much of a headache is the person getting into? Bigger alt = bigger case which in some motors I've seen, how do you ever get it to fit?!? Do you have to make major changes just to make it fit?

The shop themselves don't see profit from HO alts, they only see profits from the caps, batteries and wiring. Is this possibly why?

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

I don't know, suppose it's a possibility, but with the mark-ups they put on everything else plus labor fees, seems like they could make more on installing an alt versus a cap.

You see, nobody can give you a straight answer because there is no straight answer. It all depends on the situation, as I've ALWAYS said, to determine if a cap is useful.

A cap is only good so far as the audio system isn't trying to pull too much from the alternator.

A cap puts just about as much of a strain as a 5 watt bulb and that's only during it's initial charge. During normal operation, it consumes even less power. For comparison, your headlights consume 55 watts, each!

A capacitor is like an electronic fuel tank that holds a charge provided by the electrical system for sudden demands for short bursts until it can charge back up.

There is something called a "charge time constant" in a capacitor. This signifies how fast a capacitor can recharge after a discharge. Since a large capacitor (0.5 Farad or higher) doesn't fully discharge, it's re-charge time is pretty quick. Overall it's a 100 times faster than that of a battery.

Adding a cap to a severely demanding system won't make any improvements.

haemphyst wrote:

---

Oh, and for the record, batteries DO create power using chemical reactions....

---

Hmmm...seems I'm right again.

It seems to me that sparky3489 spent some time practicing law.  sparky3489, just make sure that you understand that batteries do not create power forever.  That's the real world!

I agree that so long as the ESR rating is at the correct point, then the capacitor will prove useful when the alternator can keep up with the demand.  Other than that,  I wouldn't consider using a capacitor for anything more than engine noise and alternator whine reduction.  I think I might look into a group of capacitors for my SPL system, but not my daily driver.  The difference between the first hit and second hit from my subs will be covered up by the fact that the bass drummer couldn't make that same intensity hit everytime or that the bass guitar player couldn't strum the string with identical strength everytime.  That's the real world!

-------------
...typically, I just run whatever I randomly pick up off the floor.
1995 Ford Ranger Supercab
MECA member
Team CSS

One other thing I failed to mention, I do believe that haemphyst is capable of presenting you with an answer if you would present him with a situation.  Actually, I think he and several others have already presented an answer to the capacitor issue.  In general, I do believe what they are getting at is that there are more important pieces of equipment to invest your money in and that in the long run, a capacitor is an expense that can be done without when the rest of the electrical system is up to par.

-------------
...typically, I just run whatever I randomly pick up off the floor.
1995 Ford Ranger Supercab
MECA member
Team CSS

sparky3489 wrote: 'A cap is only good so far as the audio system isn't trying to pull too much from the alternator.'

So you agree that the Big3 and HO alt. should be done before adding a cap? Well, alright!

wormy wrote: 'there are more important pieces of equipment to invest your money in...'

Like i've told you before in previous discussions, sparky3489; if you want to tell people to spend money on something that should be considered being done AFTER the Big3 and HO alt., then fine. -I have noticed recently on Yahoo!Answers is that you've been telling people of the importance of the Big3 and HO before recommending a cap. Hmm...

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

wormy] wrote:

---

sparky3489, just make sure that you understand that batteries do not create power forever. 

---

Since you don't know the whole debate, I'll let you in on it.

It was proposed that a battery DOESN'T create power by chemical reaction, AT ALL, by Jmelton86. That somehow electricity was magically being created with no explanation. He and I went round and round about this on another forum until he finally posted that question here - and got totally schooled on it.

[QUOATE=wormy]In general, I do believe what they are getting at is that there are more important pieces of equipment to invest your money in ...[/QUOTE]

Where to begin...this could be said about anything, wheels on a car, fuzzy dice from the mirror, etc.

A. It's not about an investment as it's NOT an investment.  Where do people get this?!?!?

B. There are those rare and special occasions where a cap is actually useful.

jmelton86 wrote:

---

I have noticed recently on Yahoo!Answers is that you've been telling people of the importance of the Big3 and HO before recommending a cap.

---

Hmm indeed. I've been stating this LOOOOONG before you ever hit the scene. It all depends on the situation whether I recommend the ALT. and Big 3 or a CAP.

If it's very clear an asker has a high powered system, I recommend the ALT and Big 3.

If it's very clear an asker has a system that doesn't require an ALT upgrade and they would like a bit better stability on the power side of things, I'll recommend a CAP.

Caps are storage devices. The voltage comming in is the same going out. They can't increase potential. Stiffening Capacitor, the name says is all.

The fact the guy on Yahoo claimed a +4 Volt gain due to caps should be a dead give away. If this is accurate, and he has 12 volts at the battery, his amps are seeing 16V ? Check me if I'm wrong but very few car electronics will work at this voltage. Then usually only competing. Also his voltage would be 18.4V with the Alternator running.

Here's your misunderstanding. I got a 4 volt gain WITH the cap as opposed to NOT having it during a significant bass track test tone. My system was dropping 4 volts without the cap.

that wouldn't be a 4 volt GAIN. It would be your normal voltage not dropping so low

This is the final answer. Caps WILL make a significant improvement on a high output system if you had say hundreds or even thousands of farads to play with. It charges FIRST and FASTER (than a battery) and discharges first and faster. It maintains the alternator voltage as long as it is not 'empty'. But this happens very quickly.This puts FULL strain on the alternator UNLESS you have 'enough' batteries (do the math) to aid the alternator. You need ALOT of capacitance to make any good bit of a difference. A very small percentage of people would benefit practically from a 'stiffening' capacitor unless they had several batteries or alternator power to charge the cap/s. So.... it is not practical to buy thousands of dollars of capacitance when you could just spentd the money on an HO alternaotr. Which is what some of these other guys have said for years. So stiff that. But really, it's basic electronics.

-------------
Clarion DXZ665mp,Lanzar 2000D,2 Powerbase Extreme 12",Pioneer 5.25" - TS-C503
JL Audio e4300,Fosgate Power 6x9,5 Farad Cap,2 Optima Yellow,205 Amp Alt

Even if you had a 1000 farad cap with a stock alt...the internal resistance of the cap would be fairly high compared to a 1 farad electrolytic cap. It would put a pretty big strain on the alternator(stock). After the capacitance was drained the voltage would be down and the alt would be fried pretty quick.

You're answer is NOT the final answer

aznboi3644 wrote:

---

that wouldn't be a 4 volt GAIN. It would be your normal voltage not dropping so low

---

Soooo... it's a gain. If something falls normally and you implement a device that gives something back, that's a GAIN. I'm gaining back my lost voltage!!!

I've notice a LOT of people miss the fact that a cap doesn't completely drain during a high current draw. It sustains the voltage from dropping out, hence the name stiffening cap.

I will say that a cap IS NOT for all situations, but in my case, it's making a drastic improvement.

a cap DOES drain...thats why the voltage will still drop

aznboi3644 wrote:

---

a cap DOES drain...thats why the voltage will still drop

---

Well now that's strange. My oscilloscope says otherwise as does the dispaly on my cap. My equipment must totally wrong.

No, a cap does not FULLY drain, but it does drop about 0.7 of a volt though.

how come in my friends system with two caps his idle voltage is at 14 volts and when the bass hits hard and long the voltage drops down to 12 volts even 11 volts sometimes???

I have a 650wrms system (I know, don't laugh!). 75amp max (fuses added together). *Factory 105amp alt, 2 yellowtops, cap, Big3 -In that order.

-Headlights dimmed before and after cap install (before Big3) the same. Voltage dropped .5-1 volt before and after cap install (*before Big3). I'm glad I got it for free!

Voltage now only drops .1-.5 volts and headlights never dim after Big3. -C(r)ap didn't do anything!

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

Keep beating that horse it should die before to long.

-------------
Big Dave

I just noticed the post and thought to myself, "Oh my God! Not the cap debate!!!" . . . again!

A cap will work on a poorly or unregulated amplifier power supply. It will help in some cases but make no difference at all in others. It does serve a purpose which can be proven by the fact that most if not all amps have an on-board cap bank.

I personally don't have one in my car but we have a 15 farad on the test bench.

I agree with Big Dave, after 27 years in the business, I knew this horse would raise it's ugly head in defiance of mortal wounds.

-------------
Prepare your future. It wasn't the lack of stones that killed the stone age.

Big Dog wrote: A cap will work on a poorly or unregulated amplifier power supply. It will help in some cases but make no difference at all in others. It does serve a purpose which can be proven by the fact that most if not all amps have an on-board cap bank.

I personally don't have one in my car but we have a 15 farad on the test bench.

*Why use a cap on a test bench? It's plugged in to the wall - the power supply is more stable/reliable than that of a mobile power supply, right?

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

Correct. But I have a battery, charger, cap setup for the bench...simply because I had 'em.

A well built power supply can be the price of a small car.

-------------
Prepare your future. It wasn't the lack of stones that killed the stone age.

Alright. So you may have benefitted a little by adding cap. What amperage is the battery charger capable of?

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

Wow, just wow.

sparky3489 wrote:

---

aznboi3644 wrote:

---

a cap DOES drain...thats why the voltage will still drop

---

Well now that's strange. My oscilloscope says otherwise as does the dispaly on my cap. My equipment must totally wrong.

No, a cap does not FULLY drain, but it does drop about 0.7 of a volt though.

---

So I have a question for you. Do you really think that a cap stores voltage? I mean do you really think that? Can you tell me what a cap does store? Also, when a cap is "drained" won't the alternator have to replace an equal amount of energy that was drained? How long do you think it takes to recharge? Do you think that the alternator feels less strain because the cap just magically creates energy out of no where?

You also stated you had a 4V improvement during bass hits after adding the cap. I don't believe this at all. Maybe someone can do some math and find out how much power would be required to cause a 4V drop in V and how many farads would actually be needed to stabalize the voltage. Seriously, if this is true you have some major problems somewhere. 4V is huge so either you are running way too much stereo equipment off a WAY to small of an alternator or you have some wiring issues(big 3 and bad factory grounds).

Lastly, you state you have an O-scope. Why do you own one? Also why are you using an O-scope to measure DC voltage? Are you an EE? If so that would answer alot of questions.

-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

auex]D wrote:

---

you really think that a cap stores voltage? I mean do you really think that? Can you tell me what a cap does store? Also, when a cap is "drained" won't the alternator have to replace an equal amount of energy that was drained? How long do you think it takes to recharge? Do you think that the alternator feels less strain because the cap just magically creates energy out of no where?

---

1. Yes, this is measurable.

2. See #1

3. Electricity, typically what is supplied with a bit of current to back it up.

4. Since a bass hit is fairly quick and a cap is extremely fast to respond and charge, the alternator has no issues responding as well.

5. Because of a caps "charge time constant" and the fact that only a small percentage of the cap is "drained", it's recharge time is very quick, 0.5 second at the most.

6. I didn't know alternators "feel" anything. Must be a magic Artificial Intelligent alternator. The trem "stiffening" is an interseting concept, eh?

These were 4 volt peaks, the average voltage drop was about 1 volt or less, still significant. 

Well, an O-scope is a bit faster and easier to read than a DMM, especially to see transients a DMM cannot display.

You really needed an explanation for an O-scope here?

sparky3489, first off, I took a bit of liberty with your quote. I am assuming you broke auex's question string into individual questions and answered them individually with your numbered responses. This is how I broke it down, and now I would like to respond in kind.

sparky3489 wrote:

---

auex]D wrote:

---

you really think that a cap stores voltage?

---

1. Yes, this is measurable.

---

I agree with this response.

sparky3489 wrote:

---

auex]I wrote:

---

mean do you really think that?

---

2. See #1

---

See #1

sparky3489 wrote:

---

auex]C wrote:

---

n you tell me what a cap does store?

---

3. Electricity, typically what is supplied with a bit of current to back it up.

---

I am slightly confused with this answer. What are you saying here? Please elaborate a little bit on this response. I am truly not trying to be smart-assed about this, but I truly want to know what your answer means.

sparky3489 wrote:

---

auex]A wrote:

---

so, when a cap is "drained" won't the alternator have to replace an equal amount of energy that was drained?

---

4. Since a bass hit is fairly quick and a cap is extremely fast to respond and charge, the alternator has no issues responding as well.

---

Here, I have an issue. The answer to auex's question is a RESOUNDING YES! However, your answer does show that you both understand and DON'T understand, completely.

Energy is drained from a cap in watt-seconds, or work over time. It also CHARGES in watt-seconds. (a watt-second, if you weren't aware, is one watt for one second) If you suddenly pull (let's just say, as an example, to keep the math simple) 100 watt seconds from the cap, but it happens in .1 second (fairly typical, actually), the current burst supplied by that cap is 1000A, for .1 SECOND. (I also want to stress that I am assuming a perfect cap and circuit, with zero resistance) Now, in order for that cap to be ready for the NEXT 1000 watt-second burst (in a bass line, at 4/4 time, what, a 1/2 second, maybe?) the source (the alternator, which we have all agreed MANY TIMES here in this forum is ABSOLUTELY the power SOURCE in a car with a RUNNING engine) must be able to charge that cap OVER AND OVER 2 times a second with 1000A bursts of current. Now, NO ALTERNATOR is capable of doing this, is it? BUT a SLA battery CAN. This is why the battery becomes so important in this circuit. Now, the battery is continually dumping this power to the cap, while at the SAME TIME the alternator is carrying the continuous load of the REST of the system's demands. That is, until the battery voltage drops, the internal resistance lowers, and the alternator's output is now being scabbed off to recharge the battery, while the battery is continuing to recharge the cap, and the alternator is trying to now power the system AND charge the battery... it's a vicious cycle, and the situation only gets worse, the longer and louder the system is played.

sparky3489 wrote:

---

auex]H wrote:

---

w long do you think it takes to recharge?

---

5. Because of a caps "charge time constant" and the fact that only a small percentage of the cap is "drained", it's recharge time is very quick, 0.5 second at the most.

---

See #4. BUT, while it is true that the cap is generally recharged to full capacity fairly quickly, (simply due to the low internal resistance of the SLA) the average recharge CURRENT DEMANDS are astronomical, when viewed strictly on a current scale. Average continuous current demands that simply CAN'T be addressed by an average alternator. All the time, pulling the average system voltage lower, and lower. The cap, because it is there for IMMEDIATE current peak demands, "covers the dimming headlights", (because the PEAK SYSTEM VOLTAGE remains where it is supposed to be, but the AVERAGE system voltage is slowly dropping... slowly enough that the lights DO dim, but not in "pulses" with the beat of the music.) and this is why many people think the cap is helping them.

sparky3489 wrote:

---

auex]D wrote:

---

you think that the alternator feels less strain because the cap just magically creates energy out of no where?

---

6. I didn't know alternators "feel" anything. Must be a magic Artificial Intelligent alternator. The trem "stiffening" is an interseting concept, eh?

---

The strain that auex is implying is "felt" by the alternator is the ever increasing current output demanded by the system drawing more from the alternator and battery combination than it was ever designed to produce on a continuous basis, all while the alternator and battery are working in an underhood environment where the temperature ever increases, reducing both of their efficiencies, causing more strain...

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Now, leave it alone... Caps:

1: Are the devil. (OK, not really)
2: CAN be beneficial, but only in limited situations.
3: 99+% of car audio issues and problems can be solved by upgrading MOST ESPECIALLY the alternator.
4: That SAME 99+% of the time, a cap will be a "band-aid on a bullet wound"
5: Should always be the LAST item added to any electrical system, and only if you want to "see the shiny red can"...

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Ok i want to throw a question in here about h.o. alt's. I have seen on here before people saying a h.o. alt does its job better at higher rpm's versus at idle speed, even read where they can put out less than a stock alt at idle speed. So, if those statements are true than, whats the point of paying the money to get one? Reason I make this comment is, I see more people really cranking there systems while parked than I do driving around at normal speed where the alt would be operating at the higher rpm's. So if the person was just parked and cranking the system, is that why I see people with x amount of batteries and caps instead of a h.o. alt? Just curious on this. I always just assumed a cap or extra battery would act like a "shock absorber" for the electrical system. I fully agree that once the car is running, the alt is providing that power, at least until it can't meet the needs, and if you go that far, the alt will eventually burn up. I dunno, just rambling.

Just to clarify, question 1 as labeled, was meant to clarify if he thought all it held was V, as opposed to storing energy and not just V. It was more toward the fact everyone was focusing on V only.

-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

This is why, when refering to capacitors, I use this very statement:

sparky3489 wrote:

---

A capacitor is like an electronic fuel tank that holds a charge provided by the electrical system for sudden demands for short bursts until it can charge back up.

There is something called a "charge time constant" in a capacitor. This signifies how fast a capacitor can recharge after a partial discharge. Since a large capacitor (0.5 Farad or higher) doesn't fully discharge, it's re-charge time is pretty quick.

Adding a cap to a severely demanding system won't make any improvements.

If your total system power is more than 1000 watts RMS you may need to:

1. Upgrade the alternator to a high output alternator
2. Upgrade to a heavy duty deep cycle battery
3. Upgrade the "Big 3" - that is to replace the power wire between the battery and alternator, the ground from the battery to the chassis and the ground strap from the engine/tranny to the chassis with at least 1/0 AWG wire.

Failure to do this will result in you replacing them anyway as the alternator can eventually fail.

---

Never have I made the "caps are the only answer" response in ANY forum as it GREATLY depends on many factors as to when to use them.

The fact is that I have seen an improvement in my system using a cap is no indication they are for everyone or every situation.

This whole thread was started by jmelton86 who seems to have skipped out of the debate in the first place.

tdsteele wrote:

---

Ok i want to throw a question in here about h.o. alt's. I have seen on here before people saying a h.o. alt does its job better at higher rpm's versus at idle speed, even read where they can put out less than a stock alt at idle speed. So, if those statements are true than, whats the point of paying the money to get one? Reason I make this comment is, I see more people really cranking there systems while parked than I do driving around at normal speed where the alt would be operating at the higher rpm's. So if the person was just parked and cranking the system, is that why I see people with x amount of batteries and caps instead of a h.o. alt? Just curious on this. I always just assumed a cap or extra battery would act like a "shock absorber" for the electrical system. I fully agree that once the car is running, the alt is providing that power, at least until it can't meet the needs, and if you go that far, the alt will eventually burn up. I dunno, just rambling.

---

There are manufacturers that make alternators that put out a good amount of current at idle speeds.

I only post when I'm at work. I work Mon. - Thu. nights. It's Mon. night so I'm back at work. What's up everyone?

-I added a cap before hearing about and applying the Big3 (fact. alt, tiny charge wire). I didn't notice any quality increase in the sound. I however did notice my headlights started slowly dimming (tis' a long drive home from work, system cranked) and the quality of  sound become bad, I thought I was loosing ground. I turned it down to about 1/2 way and turned sub amp off. The treble/mid started sounding better as soon as I turned my sub amp off! The factory charge wire, right after this instance it seems, turned brown right by the alt. The alt. must've been getting pretty hot, i'm glad I turned my sub amp off! This is the exact reason (I didn't get it til' reading the past couple of posts!) why I started this post -Since then i've done the Big3 and it seems to 'hold up' so i've left the cap. After reading the rest of this thread, though, i'm taking it off! -Thanks haemphyst!

Oh, sparky3489, had you been telling people just this;

sparky3489 wrote:

1. Upgrade the alternator to a high output alternator
2. Upgrade to a heavy duty deep cycle battery
3. Upgrade the "Big 3" - that is to replace the power wire between the battery and alternator, the ground from the battery to the chassis and the ground strap from the engine/tranny to the chassis with at least 1/0 AWG wire.

Failure to do this will result in you replacing them anyway as the alternator can eventually fail.

*****

i'd've had no reason to start this post because I had seen nothing like this until I started answering questions with 'the Big3' -it wasn't until I questioned you personally on cap usage that I somehow noticed it.

Anyways,, I hope everyone has/is learned/ing something from this thread. I've learned exactly what happend 'that night'. Cheers

-------------
2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

1) I agree with what haemphyst said 'cause it's what I stated earlier. If it does some "work" then add it otherwise throw it in the recycle bin for next time - it aint complicated.

2) This is my last post on this thread. I'm too busy to talk in circles - I've got to solve the chicken and the egg theory before noon.

3) I have a new idea for debate: Is a ground an input or output?

-------------
Prepare your future. It wasn't the lack of stones that killed the stone age.

It depends on the theory you are dealing with. In MY opinion, it is the input, the side with the EXCESS of electrons, and the positive lead is the actual electron return.

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Big Dog wrote:

---

Is a ground an input or output?

---

It is neither without opposition.

That' my final answer.

Guys......I was jus kiddin'

I wouldn't do that here.

Maybe in a new thread

-------------
Prepare your future. It wasn't the lack of stones that killed the stone age.

Back to it then...

I quote from someone else on another forum,,,

]First wrote:

---

of all, reducing dimming lights isn't really what a capacitor is for. The purpose of a power supply capacitor is to provide a stable voltage supply for an amplifier during musical peaks, thus improving headroom. If it helps with dimming lights, that's a bonus; but if the dimming is what you're trying to fix, you'd be much better off connecting the cap to the headlight wires. (In fact, there are people who've successfully done exactly that, using much smaller capacitors).

The power demands of an audio amplifier are unlike anything else in the vehicle. Most vehicle electrical systems have a relatively steady current draw that only changes when you switch them on or off. The amplifier's current draw when playing music is always changing. On average, the alternator may easily be capable of handling the demand of the audio system, but alternators aren't designed to handle sudden spikes in current draw. The voltage regulator may not be able to adjust quickly enough, or the alternator may just be overloaded very briefly, which leads to a voltage drop. This doesn't necessarily mean you need a new alternator.

The capacitor can store a voltage at nearly the level of the alternator's output. It's not limited to 12.8 volts like a battery. During brief musical peaks the capacitor can provide current for the amplifier. Of course the cap then needs to be recharged, so the load on the alternator isn't reduced--but by that time the musical peak is over and any voltage drop won't have an effect on the sound. During quieter passages, the amplifier can produce music without distortion even if it doesn't have 14.4 volts to work with. Note that we're talking about very short periods of time, here; it doesn't take long to discharge a cap, and it doesn't take long to charge it again, so it's ready to go for the next musical peak (in theory).

The "caps are useless" idea has come about mostly because people have been misinformed about what a capacitor can do.
--They won't help prevent alternator failure.
--They can't store very much charge, so they don't help with longer musical peaks, like sustained bass notes.
--They don't make the bass louder: higher voltage isn't the same as higher gain.
--They don't help if an alternator is just too small, and is continuously overloaded.
--They won't necessarily reduce dimming much, because they still need to be recharged.
--High-farad capacitors typically have a high internal resistance which makes them useless. In general, it's better to have five 1-farad capacitors than one 5-farad capacitor.

When Javin (Jmelton86) pulls out his Richard Clark "caps are useless" forum link, the discussion is about high-farad capacitors (although it's been used out of context to make it look like he's talking about all capacitors).

Anyway, "stiffening" capacitors do have a useful place in car audio; but you have to know what they can do, what they can't do, and in what situations they'll be useful, or you're likely to be disappointed in the result.

---

Feel free to discuss amongst yourselves.