[tim0shel]

ESR = Equivalent Series Resistance
The following have ESR
Power supply
Amp
Battery
Cap

So if you had 100 amps flowing through a resistor of .017 ohm the voltage drop would be
1.7v

300 amp flowing through would be a drop of 5.1volts

Watt= How much work can be performed but does not tell you for how long it can sustain that work.

Joule= can tell you, it’s a watt second, so 10 Joule can provide 1 watt per 10 sec. or 10 watts for one sec. Or how ever you can divide it up.

Formula for determining Joules stored in a capacitor
Take on half of the capacitors value (farads) and multiply it to its voltage squared.
1 farad cap at 14 volts
.5 x (14x14) = 98 Joules

A cap just stores energy

Batt. Don’t they have the potential to produce electricity by a chemical reaction

Cap just stores electrons on their plates in the form of electrostatic charge.

Ei. What is the joules of a 65 amp hour battery
So a fully charged batt. With a 65 amp draw would have about 12.2volts and by the end of the hour it will be down to 10volts about dead.
Using the voltage at about 11volts joules would be 2,574,000 joules
So after removing the 2.5 million joules from the battery it probably doesn’t have but more then hundred joules left.
You can almost drain the batt. And never drop below 10 or so volts. If a cell or something goes bad yes but its pretty much drained around there.

So if you charge a 20 farad Capacitor to 14 volts we know with our formula its 1960 joules. Using that cap in a audio system and load it till it drops like with the battery and drops to 10 volts how many joules will we have removed from the cap? What is left in the cap will be useless cause our system will never drop below the 10 volts unless battery is bad.
The cap will have 1000 joules that we can not use because the voltage is not dropping any more than the 10 but most amps etc. will not work at this voltage.

Power that is delivered to the stereo by the battery and alternator bypass the cap. They merely flow by its terminals if the cap drops below the battery or alternators voltage the current will flow into the cap until it reaches the same voltage as battery and cap.
But if the cap has more voltage than the battery or alternator the current will flow out of the cap to the battery or amp.

Now we know that the cap has an ESR so if this 20 farad cap has this of .017 and we put a load on it of 100amps. Its charged up to 14.2volts now what will our voltage be at when we draw the 100 amps out of it?
Will be 12.5 volts
This is 100 ohms of resistance. The wattage is 1250 watts from you cap . 12.5x 100amps = 1250 watts
The cap is actually putting out 14.2volts x 100amps = 1460 watts but 170 watts of power is actually lost in heat in the ESR of the cap. That’s a loss of 13%
So if we change the 100 amp draw to 300amp draw it equals to 56% of the stored energy is lost. So there are 1530 watts lost in heat.

ESL = Equivalent Series Inductance

 

[Carolina Boy]

BREAKDOWN ON WHY I DON'T GIVE A [email protected]#K !!!!

:rofl::rofl::rofl::rofl::rofl::rofl::rofl:

 

[Retro]

I have no idea what any of this means. However, it if wasn't for people like this that break shit down, then half the shit we have wouldn't exist.

Thanks for doing whatever it was you did here. I am sure that some one will be able to post this in lame mans terms so that the rest of us under stand it....

 

[Knowklew]

I have never used caps in any of my systems, because I believe they are a bottleneck for power, if done correctly a system shouldnt need a cap. you would be much better using a second battery or upgraded alternator. it has been said before and i will say it again, caps are just bandaids.

 

[TrailBlazer SS AWD]

You Need A "Flux Capacitor", It Can Provide 1.21 Giga Watts.

 

[tim0shel]

When i get some more time i will break it down for yall lol.
I was thinking it was a little much but all and all it does need a summery lol

And Randy your crazy just not right haha

 

[PCbyTC]

You are mistaken...

You Need A "Flux Capacitor", It Can Provide 1.21 Giga Watts.

The Flux capacitor REQUIRED 1.21 Giga Watts to activate. I will now kill myself for actually posting that needless chunk of the 80's :iamwithstupid:

 

[BBA]

I agree a cap alone is not very effective.

But, I do think you should read my headlight dimming post below. The way to make it worthwhile is using a cap behind an inductor (low DCR and high L type, such as a toroidal) and it will use the cap for instantaneous current and use the inductor to dampen the instant current drain from the alternator.

It works and it also completely eliminates alternator noise, such as any LC power filter will do (A cap alone is not enough to filter out the noise).

This method works really well for the models with the load sensing hall effect on the negative terminal, because it eliminates the alternator voltage overshoot/undershoot condition caused by the response delay the sensor has bult in. For example, with an oscilloscope I saw a 1-1.5v instant drop in battery voltage when bass would hit at volume and the current sensed would cause the alternator to over compensate a half second later. With the LC filter, now the battery voltage never drops, it actually goes up when heavy bass is hitting, and the ramp up is very gradual. Gotta love a good design. (And this is with stock battery and alternator).

 

[BILL]

The Flux capacitor REQUIRED 1.21 Giga Watts to activate. I will now kill myself for actually posting that needless chunk of the 80's :iamwithstupid:

Information like this needs to be kept secret. Biff might be reading the forum.

.

 

[VaderSS]

Caps only store power...they say you need one to keep your lights from dimming but they are really good for competition when you need a lot of bass at once. It help keep a large flow of power to the amp and on to the sub so it will keep consistant tone when trying to reach max DB. there you go

 

[Warwagon]

The caps have some use as BBA said above. They are only a single part of a full noise filter circuit design. Even on their own they have some specific uses. Ever open your amp up and see all the big filter caps it has in it already?

You missed the part where the caps provide the energy, by keeping the voltage steady, for the big punch your amplifier provides. Lower voltage to your amp = reduced punch. Add a Cap to keep the voltage up for that punch the better it will sound. The longer the punch lasts the lower the voltage will go. Aka stepping from the cap's energy to the limits of the batteries to hold the voltage up. The Alternator can't change it's output fast enough.

Caps mainly filter noise by keeping the circuit voltage steady. They charge when the voltage gets higher effectively clamping the voltage spike until the cap charges to that voltage. Then when the voltage drops the cap discharges keeping the voltage high. They provide instant power where an alternator takes time to rotate and bring up the field coil strength. After all the field coil in the alternator is one hell of a big inductor. (More field coil strength means more current and voltage out of the alternator. Voltage changes depending on load.) Even a battery has a voltage drop before you get full power from them. In effect caps keep the voltage steady while the current is changing.

On a DC circuit caps can short AC "noise" to ground. The 3 phase AC noise coming out of the alternator riding the 12V DC is a perfect example.

So it is the small voltage drop/rise you get without a cap that takes your award winning system out of the competition letting the people that have caps set up right win. Because of their benefits the fact they may waste energy is not a concern unless you overheat and explode the cap.

 

[tim0shel]

Everyone has good points and I wasnt saying not to use one at all!! In alot of cases it will work for the application. This was more of my own opinion and in my systems extra batterys is the way to go and have to go. I look at it as in using a battery over a cap if you have the room. Deep cycle one.
Well this has been my first post in forever guys. Ive missed everyone. Im borrowing wifi right now to get on lol.

 

[sixols2]

welcome back Tim

 

[kytbss]

Caps are just eye candy for people that dont know better. They are just a fancy way to watch your voltage.

 

[tim0shel]

Yep they can be just that. I had one in my Beetle that wasnt even hooked up was there as part of the install lol. It was one of the big square ones 15 farad

 

[BPT_C20]

Caps mainly filter noise by keeping the circuit voltage steady. QUOTE]

To Warwagon, you should listen.

He appears to have a firm grasp on this subject.

 

[neurotictim]

Caps have their uses, but if you haven't done the big three and don't have solid grounding throughout, they're literally wasted money.

Any car audio system should be treated as a system and not as a collection of components. Over the years of installing and tuning car audio, both as an amateur and professionally, I have seen hundreds of cars with voltage problems that are solved by nothing more than proper grounding.

:EDIT: I know it's a zombie thread, lol. Still some good knowledge up there.

 

[mitch kramer baby!]

Caps have their uses, but if you haven't done the big three and don't have solid grounding throughout, they're literally wasted money.

Any car audio system should be treated as a system and not as a collection of components. Over the years of installing and tuning car audio, both as an amateur and professionally, I have seen hundreds of cars with voltage problems that are solved by nothing more than proper grounding.

:EDIT: I know it's a zombie thread, lol. Still some good knowledge up there.

I had a friend of mine that had like a 2k setup in his SUV and every 1-2 months would fry shit, it would never sound good. He had a shop install it and kept going back for warranty. He never had to pay but after 6-7 trips for a few hours or dropping the truck off for days got tired of it. I told him I'd look at it and he said no I don't want them to not warranty it. So his amp fucked up and he got a new one and asked me to look at it. The fist thing I did was look at the ground. It was on paint and like a rubber sealant shit. I wire buffed it to bear metal and it's been perfect since!!

Ground your shit people!! Lol