capacitors for burping?

[matthubb123 11]

just was wondering if i should by this capacitor i was looking at. So would a cap benefit me in a burping scenario? my car will be running 2 sundown 4500's and a sundown 100.4(mids) with a 275amp Mechman H.O. alt with 5 XS power 14 volt batteries. any opinions on the soundstream sc-40CA 40 farad ?

http://www.woofersetc.com/p3257/SC40CA--Soundstream-40-Farad-Digital-Hybrid-Super-Capacitor.htm or

http://www.woofersetc.com/p3784/SCC1--Lightning-Audio-50-Farad-Carbon-Capacitor.htm

Edited January 13, 2011 by matthubb123

[CrownVic 15]

What problem are you trying to fix?

[CrazyKenKid 64]

a little off topic but batcap also make something like this

http://www.batcap.net/Products/BatCapProductLine/BatCapPowerPack/tabid/92/Default.aspx

batcap makes awesome stuff for burping!

[CrazyKenKid 64]

off topic but how are you charging these 14volt batteries?

[ssh 924]

off topic but how are you charging these 14volt batteries?

16v alt for stereo, stock alt for stock electrical.

or step downs

[CrazyKenKid 64]

off topic but how are you charging these 14volt batteries?

16v alt for stereo, stock alt for stock electrical.

or step downs

well i know how to charge them and you know but... does he know, was the question!

hell I knew someone trying to run 14v off of his 12v alt! ya he told him he was dumb! he though the 14s would work just as well on a 12v since 12v charges at 14.4....

[ssh 924]

off topic but how are you charging these 14volt batteries?

16v alt for stereo, stock alt for stock electrical.

or step downs

well i know how to charge them and you know but... does he know, was the question!

hell I knew someone trying to run 14v off of his 12v alt! ya he told him he was dumb! he though the 14s would work just as well on a 12v since 12v charges at 14.4....

true true. At least when the OP reads this, he'll either concur or learn something new and not drain his batts

[matthubb123 11]

off topic but how are you charging these 14volt batteries?

Im really just trying to find out what advantage if any this will be to my electrical system during a burp scenario.

was told to run my alt in the 16v range by Matt from Mechman, has the adjustable volt gauge coming off the alt to set between 12v-18v

there will also be a XS power batt charger in the trunk, along with my generator for comps

[helotaxi 46]

It will give you the same benefit that it gives in every other scenario. None. More, bigger batteries, not caps.

[///M5 2,833]

One other benefit, your wallet will be lighter and someone's marketing scheme richer.

[altoncustomtech 773]

The idea that a capacitor can help anything at all is that it holds a fair amount of current that can be utilized faster than a battery can. However, there's some time constants involved in the amount of current that the cap charges and discharges in any given scenario. The idea is that in a sudden demand for current draw the cap can help "stiffen" the voltage in the circuit and prevent the voltage from dropping, and it can, but only to a point. As far as what you're asking for you particular application it will not help at all, even by the theory that involved the use of caps in the first place. For burping scenarios you're playing a tone for a few seconds, right? There's no dynamics, no fluctuations, just constant demand for whatever the time period is and anything the cap could do to help would have been used up in the first few milliseconds and could/would actually become a drain on the rest of the electrical system as it would continue to attempt to charge back up. This is a VERY basic description of why it does nothing to help, especially in high current demand situations they simply don't work. Now, if a persons headlights are dimming and flashing like a light show at a concert one can put a cap on the headlights and get stability in the voltage for them, as has been suggested before, BUT it does nothing to solve their real problem. It's just a real world example of them working, but that is also not a high current circuit.

As M5 said, the only benefit is to the companies that make them. Marketing hype and unknowing users who swear they have helped happening for years has people believing there's any real benefit.

[CrazyKenKid 64]

The idea that a capacitor can help anything at all is that it holds a fair amount of current that can be utilized faster than a battery can. However, there's some time constants involved in the amount of current that the cap charges and discharges in any given scenario. The idea is that in a sudden demand for current draw the cap can help "stiffen" the voltage in the circuit and prevent the voltage from dropping, and it can, but only to a point. As far as what you're asking for you particular application it will not help at all, even by the theory that involved the use of caps in the first place. For burping scenarios you're playing a tone for a few seconds, right? There's no dynamics, no fluctuations, just constant demand for whatever the time period is and anything the cap could do to help would have been used up in the first few milliseconds and could/would actually become a drain on the rest of the electrical system as it would continue to attempt to charge back up. This is a VERY basic description of why it does nothing to help, especially in high current demand situations they simply don't work. Now, if a persons headlights are dimming and flashing like a light show at a concert one can put a cap on the headlights and get stability in the voltage for them, as has been suggested before, BUT it does nothing to solve their real problem. It's just a real world example of them working, but that is also not a high current circuit.

As M5 said, the only benefit is to the companies that make them. Marketing hype and unknowing users who swear they have helped happening for years has people believing there's any real benefit.

aww i thought caps had there place but it wasn't a big place!

plus 1 for you kind sure nice explanation!

[matthubb123 11]

The idea that a capacitor can help anything at all is that it holds a fair amount of current that can be utilized faster than a battery can. However, there's some time constants involved in the amount of current that the cap charges and discharges in any given scenario. The idea is that in a sudden demand for current draw the cap can help "stiffen" the voltage in the circuit and prevent the voltage from dropping, and it can, but only to a point. As far as what you're asking for you particular application it will not help at all, even by the theory that involved the use of caps in the first place. For burping scenarios you're playing a tone for a few seconds, right? There's no dynamics, no fluctuations, just constant demand for whatever the time period is and anything the cap could do to help would have been used up in the first few milliseconds and could/would actually become a drain on the rest of the electrical system as it would continue to attempt to charge back up. This is a VERY basic description of why it does nothing to help, especially in high current demand situations they simply don't work. Now, if a persons headlights are dimming and flashing like a light show at a concert one can put a cap on the headlights and get stability in the voltage for them, as has been suggested before, BUT it does nothing to solve their real problem. It's just a real world example of them working, but that is also not a high current circuit.

As M5 said, the only benefit is to the companies that make them. Marketing hype and unknowing users who swear they have helped happening for years has people believing there's any real benefit.

Thank you, that was exactly what i was wanting to know. my electrical system should be fine, I just wish there was room for another h.o. alternator under the hood.

[helotaxi 46]

The idea that a capacitor can help anything at all is that it holds a fair amount of current that can be utilized faster than a battery can

The fundamental flaw with caps is that both of those ideas are without merit. It barely holds any *usable* energy and it cannot deliver it any faster than a battery can.

[onebadmonte 235]

Here is a nice little read on capacitors:

Capacitors the final word

[Godsmack 361]

Best quick explaination for a capacitor I have ever read or heard:

Using a capacitor to help your electrical is like putting a band aid on something that needs stiches.

J

[Randal Johnson 544]

just was wondering if i should by this capacitor i was looking at. So would a cap benefit me in a burping scenario?

[karpowr 0]

Best quick explaination for a capacitor I have ever read or heard:

Using a capacitor to help your electrical is like putting a band aid on something that needs stiches.

J

It seems like those other high power capacitors are really high for the price....like the cost of another XS power battery.

[Randal Johnson 544]

It seems like those other high power capacitors are really high for the price....

They wouldn't even make good boat anchors ... They would contaminate the water ...

[helotaxi 46]

Here is a nice little read on capacitors:

Capacitors the final word

That thread is chock full of stupid on so many fronts. Typical for that forum.

[ibanender 2]

Here's the real deal with caps if you do the math. 1 farad of capacitance is good for 4 amps of current for 3 seconds on 12.6 volts. So, say you went with a 40 farad, you'd have storage for 160 amps for 3 seconds. Keep in mind, that's till full discharge. So, if you have more than 1500 watts, it probably won't do anything for you.

Now, in a real world scenario, a friend of mine got eight 50 farad caps to pretty up his install with his 8 Memphis 4kw's. That means he had 210 amps of storage. 4kw's draw over 400 amps of current (don't know exactly, clamp only goes to 400) and has to go directly through the cap. He gained around 1 dB by taking out the caps. This was in an extreme vehicle, burp only.

[El1T3Bass 0]

It will give you the same benefit that it gives in every other scenario. None. More, bigger batteries, not caps.

this... ive read some stuff on how caps can help for 30k+ systems that burp but never saw anything solid on it...

[ibanender 2]

It will give you the same benefit that it gives in every other scenario. None. More, bigger batteries, not caps.

this... ive read some stuff on how caps can help for 30k+ systems that burp but never saw anything solid on it...

If it worked, you'd probably see it in 170+ vehicles instead of 30+ batteries.

[helotaxi 46]

Here's the real deal with caps if you do the math. 1 farad of capacitance is good for 4 amps of current for 3 seconds on 12.6 volts. So, say you went with a 40 farad, you'd have storage for 160 amps for 3 seconds. Keep in mind, that's till full discharge.

Show your math. Remember that the only usable energy stored is that in the voltage between whatever your alt voltage rests at and the battery voltage. That's also in a perfect world where there is no ESR to worry about. I've done the math. Usable energy in a perfect world (no ESR) is 0.5 amp-seconds/Farad.

[ibanender 2]

Here's the real deal with caps if you do the math. 1 farad of capacitance is good for 4 amps of current for 3 seconds on 12.6 volts. So, say you went with a 40 farad, you'd have storage for 160 amps for 3 seconds. Keep in mind, that's till full discharge.

Show your math. Remember that the only usable energy stored is that in the voltage between whatever your alt voltage rests at and the battery voltage. That's also in a perfect world where there is no ESR to worry about. I've done the math. Usable energy in a perfect world (no ESR) is 0.5 amp-seconds/Farad.

(farads*voltage) / seconds

There are a number of "what if's" like ESR, but the math I found back when I was compiling a spreadsheet of equations is what you see above. If I can round up a capacitor this weekend, I'll do a real world test of draw over time to verify.