100 Farad cap; bogus or just plain overkill?
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jmsochetti45 Unregistered guest | I was looking around online for a cap and came across a 100 farad one by lanzar. I'm not going to get it, but is it even possible, and if so is it even worth it? |
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dvs Unregistered guest | that's retarded-huge I don't see how anything other than a rolling sound platform could need a cap that big. Even then... if this is legit, there has to be a demand for the product for a manufaturer to make one. So the question is... who are these people who need 100Farad caps? And why can't I hear them now? |
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Unregistered guest | lol point! but why dose audiobaun make a 34 inch sub with a 5000 watt rms rating thats right 5000 rms dont believe go to www.thezeb.com i believe they still sell them for about 2 grand |
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joejoejackson Unregistered guest | you would need a cap that big, when runing around 5000 or 6000 watts RMS in a sound compatition and need to sustane the SPL for at least 2 secound for it to count... and yeah a say 15 farad cap will work to run 5000 watts RMS but it will only work for one beet or so, and the voltage will drop in less than a second |
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Gold Member Username: SubfanaticWalton, Ky Post Number: 3326 Registered: Dec-04 | ok guys, the rule of thumb is 1 farad per 1000 watts rms, so for 5000 watts rms you would only need a 5 farad cap, also. that audiobahn isnt very strong, the mts take up to 6000 watts rms, and thejackhammer takes BURPS of up to 50,000 watts rms, that would need a 50 farad cap, but there are also people who run 100,000 watts through there car who would need this cap, its not really that big of a waste guys |
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Miah Unregistered guest | I just slipped into this site and noticed your thread. No intelligent mobile audio enthusiast will use capacitors over 5F. The reason? A car battary has billions of Farads of capacitance and a top of the line performance battery only runs around 200$. Therefore when the cost of capacitors reaches 200$ you switch to batteries. Incidentally; a 100 farad capacitor would drain a single battery on the third pump, just because of the manner in which they draw. |
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Gold Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 1267 Registered: Sep-04 | A car battary has billions of Farads of capacitance I don't how you came up with that figure, but even if were true just how useful would a battery's "capacitance" be while the engine is running and ALL power is being provided by the alternator? Answer? Zippo. As far as a 100 farad capacitor draining a battery in 3 pumps, thats the most ridculous thing I've ever heard. I'll spare you the math, but do you know how much energy is stored in a typical 12v 100 amphr deep cycle battery? Answer? 4,320,00 Joules Do you know how much energy it takes to charge a 100 Farad Cap from 0-12v? Answer? 14,400 Joules What does this mean? This means that you could charge 300 100 Farad caps with one 100 amphr 12v battery. Any "intelligent mobile audio enthusiast" realizes that the voltage will NEVER drop to zero while a system is running, so the actual energy required to recharge this cap each "pump" will be substantially less. This doesn't mean that those 100 Farad "supercraps" do anything to improve transients as a typical electrolytic cap can, but you need to get your facts straight or at least provide some sort of intelligent evidence to back things up before maikng such outrageous claims. -Fishy |
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Gold Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 1268 Registered: Sep-04 | [edit] 4,320,000 Joules |
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Gold Member Username: SubfanaticWalton, Ky Post Number: 3474 Registered: Dec-04 | haha fishy, you beat me to it |
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Unregistered guest | LOL dang um got to hand it to fishy he knows what he is talking about man and your a boat captin wow amazing ::clap:: props |
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Anonymous | You do the same thing like comparing RAM with a HARD-DISC. A cap is like the RAM in a PC and the battery is like the HD in a PC. 512 MB RAM costs more than 80 GB HD. But many people buy >= 1024 MB. Why ? For example, RAM is faster. Of course, it exists much more reasons... Example in the car : If you want to start your motor without a battery (hypothetically) only with the cap, you need at least 100 Farad to have enough power for 3 seconds of starting. What is 1F ? My carradio powers off if I start the motor. So I exchanged the 36Ah / 300A standard-battery with a new Varta 66Ah / 600A battery. That was not enough, the inner-resitant of the battery must be a little bit to high. The voltage falls under a magic value while starting. Because of this I think on buying a cap. A 12V loaded 1F-cap would loose about 6V after a 0,03s. Would you connect the power-input of the amp (140watt) only with such a cap, the cap would be nearly empty (1T) after one base-beat. |
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Um.... Yea.... Forgots.... Unregistered guest | Look, heres whats really going down, caps are going to improve any amp. Not by giving it more power, but giving it more instant power. Batteries can put out power only so fast. Yea, you could go out and get one of those 1,000 cranking amps type of huge batteries, but they cant put out 1,000 amps very fast at all. Maybie on a dead short they could, but thats it. 100 farads isnt really much power at all. Reletively speaking, it is almost nothing. A 2000mAh AA rechargable battery has the same power as a 7,200 FARAD cap (at only 1.2v) So you may think thats alot of power, but if you know from experience, AA batteries arent going to be starting your car. They put out marginal current for a long period of time. AKA they have a high internal resistance. Capacitors have a very very low internal resistance and thus can put out all of thier current right when it is needed, wich is usually now... And yea, you know those 100 farad caps, those suck for use in a car, unless it's running your car radio while starting with a 10A diode after it. They have a very high internal resistance, and it takes them much longer to charge and discharge. Questions? Ask... |
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New member Username: DudesjarNorth Dakota Post Number: 8 Registered: Jun-05 | well you seem to know battery's, i was thinking about buying a stinger sp2750 or whatever it is. they also have the sp1700. they have a low internal resistance, but would it be practical. i am going to be running the 2004 alpine 1800watt rms monoblock amp. so your looking at like 150-200 amps. should i just get an optima yellowtop and then get a cap, or a couple caps. also would the big stinger power2 battery hurt my starter because it can supply so many cold cranking amps? anyway does it matter what brand of caps you use or are they pretty much all created equal? |
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Um.... Yea.... Forgots.... Unregistered guest | A good battery is required for anything that takes alot of power, if you have a bad battery, ur amps gonna suck. Optima makes great batteries, so go with one of those. But as far as caps go, if you are using anything under a 2 gauge wire, you really dont even need a cap. But they can help, and the audiobahn ones look nice too. FOr the amp youd need about a 2 farad cap, anything over that is usually overkill and too $$$ to be pratical. Now about brands, yes it does matter, all caps are different, but they rarely tell you the ESR (rated in ohms) but if they do, the lower the better. Dont get one of those 'digital' ones with snazzy volt meters on them, they suck. Get a basic cap around 2 farads and up. And the optima isnt going to do anything to your car, except make it start better and faster by supplying the current it needs, insted of having it kill your battery for those seconds while it's starting. (why the radio turns off) |
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New member Username: DudesjarNorth Dakota Post Number: 10 Registered: Jun-05 | alright, but you didnt tell me if the stinger one would be better or overkill. it supply's 3400 amps. the stinger battery (i dont know how much it costs) but it woudl fit in my truck, and its a more powerfull battery. i think at 40Ah it will last 3.8hours till the voltage drops to 10V, but i could be mistaken it could be more. i'll check to see if i can get some specs on an optima battery. i can also get a yellowtop for like 140 or 160. a good friend owns a bait shop and can have one ordered. But yea i'll prolly buy a stinger cap, but im gonna run 0 gauge from the battery and then distrubute it from there. but i plan on running that amp and another alpine amp for components in my kick panels. i have a clarion 100W RMS straight thru amp running them now. but yea any more help would be appreciated! |
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Um.... Yea.... Forgots.... Unregistered guest | The stinger one should work great, nothing is ever overkill in my mind. The bigger, the better when it comes to most cr audio. Except woofers. that audiobahn 34 incher sucks for the price size, and weight. 15 inchers and bigger are only good when used with two or more 12's, 10's or 8's. 15's move to slow to acurartely reproduce many frequencies. Go with audiobahn 10's with alot of travel (big surrounds) And, a bigger battery and thicker wire (try to get into the aut's insted of 0 gauge, wich isnt really a gauge, it's called aut) will always beat out a huge cap. But still does not replace a cap. |
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New member Username: Pricey1985Sydney, NSW Australia Post Number: 6 Registered: Jul-05 | most of the time having a cap in a car sound system is just a "wank factor" |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7882 Registered: Dec-03 | those large capacitors and battcaps are total BS. the ESR is far too high to be effective with them, using carbon based capacitor banks internally. total junk. capacitors don't help voltage rails anyway. the only things a capacitor will do is reduce propogation delay and filter AC ripple neither you're likely to notice anyway |
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Silver Member Username: HellbenderLos Angeles, California USA Post Number: 111 Registered: Apr-05 | this post is still alive? haha |
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Silver Member Username: Dz43893Chicago, Illinois United states Post Number: 144 Registered: Jun-05 | i wish i could join in on this thread but idk what theyre talking about |
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c to da muthafukin...uspid Unregistered guest | damn glasswolf!!!!! you beat me at posting that, yeah i know alot about batteries, it still looks cool though if you have a 100 farad capacitor |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8374 Registered: Dec-03 | heh that name reminds me of that movie long kiss goodnight. "never make an assumption! it makes an a** outta u, and umption!" -Sam L Jackson that was some funny stuff there |
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New member Username: Gpz1100Post Number: 6 Registered: Jul-05 | 100 farad capacitors??? I'd like to see just how big this bad boy is assuming such a cap actually exists (doubtful). Fishy: I doubt many in here (besides glass), actually even know or understand the concept of transient response. It'd be interesting to measure what the nominal power requirement is of a system with 2000W rms amps operated at moderate listening levels. I bet it would be under 500W tops.. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8412 Registered: Dec-03 | there are 100Fd capacitors around for sale.. and 50Fd models, but these high capacitance jobs have a high ESR, because they aren't like the 1Fd electrolytics you're used to. They're carbon film capacitors if I recall, and they're really not suited to these applications.. but due to the big 'numbers' they make great eye candy for people who want bragging rights about having the biggest cap. anyway, they do exist, and look more like an amplifier casing from something like a JBL bp600.1 than a cylindrical capacitor you're thinking about. |
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Gold Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 1462 Registered: Sep-04 | Now we remove the batteries power wire(both) and geuss what? the interior lights stay on, and stay on and stay on and stay on. I am half tempted to try and start the vehicle off it. Posted by JBONDOx somehwere in this giant thread(quoted page 13)(copy/paste to address line): What I think might be a better application for these things would be in race applications where weight is important. Not sure but it seems like these things could have enough stored energy to replace starting batteries to run an ignition system(act as voltage base when voltage regulator temporarily "removes" the alternator from the electrical system). In other words, start the thing with a removable external battery bank or mechanical starter. Its not a good idea to disconnect a car battery while the engine is running, but I was wondering if that might just be possible with one of these supercaps installed. The thing might just be capable of providing a sufficient 12 volt DC offset(base) to keep the engine running when the voltage regulator kicks in. Just a thought. I really don't see much use for these things otherwise...... other than lining the pockets of certain mobile audio manufacturers and sales personnel.  Then again a small 12v battery might work just as well. -Fishy |
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