***Why you don't need a capacitor***
08-13-2007, 05:29 AM
#27
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i would say yes because when the 2 subs hit hard it will strain the alternator bad and also draw from the battery causing ur lights and other electronics to dim(like when stopped at a light blasting your music i bet your lights dimm a lot) so yes i would say a cap would save your alternator and other components from going bad from voltage spikes.
look at it this way, if your lights are dimming when your driving or parked with the engine running then the chances are that you need a cap, new higher output Alternator or dual battery setup (of what if u wire wrong it will blow ur ECU) so out of all these the cap is the cheapest of them all
look at it this way, if your lights are dimming when your driving or parked with the engine running then the chances are that you need a cap, new higher output Alternator or dual battery setup (of what if u wire wrong it will blow ur ECU) so out of all these the cap is the cheapest of them all
08-29-2007, 11:18 AM
#29
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i didnt read the post so i dont know if what im saying has been said yet,
i to worked at cicirut city (3yrs) i tried my best to not sell caps for the reson of dimming lights . (uness we were close to budget anb i neded the extra install pointsLOL)
heres why adding caps and extra batts to a stock electcal system is a bad idea.
amps dont make power they convert it .
if you have 1000wrms amp it dosnt just pull that power out of no were .you car has to be able to make 1000watts ,
(this is a extrem example of what not to do)
most cars run at about 13.9v when running lets say you have a civic dx with an alt. that makes about 60-70amps at full tilt.
so you take your civic and you put a big phatnacky system in it (2)1000wrms amps ,big 500wrm 4ch and just for shiggles some neons and stuff...it all gets hooked and ...wow you light now dim when the bass hit...wonder why? lets find out how much crrunt you are drawing from your cars charging system... divide your systems rms by your cars voltage 2500w/13.8v ...wow your trying to pull 181 amps from an system that only makes 70amps...so what happens when your alt cant deal whith the load , it truns to the cars battry. now your thinking no prob my batt is like 700cca (cold cranking amps) it can hadle the crurrnt draw...it can but only for a few mins..lol batts take a long time to recharge. and since your alredy drawing more current then the alt can supply your now draning your batt quicker than it can recharge. at this point most people just see there lights dim and throw a cap on there system...fixes the light dimming for while, but now you just put more stress on the charging system, not only is you alt tyring to keep the batt charged and the car running , its got a new job of trying to keep the cap charged aswell ,this is also why throwing another batt in is a bad idea too. .So what happens next? most likely your alt says screw this i quit...your batt soon follows and now your stuck on the side of the road becasue you put more strain on your cars elec.system than it was ever desinged to handle. (all a cap dose is store engery ,and guess what ,pull your amp apart.. its full of caps ,if its well made it alredy got all the capacitance it needs built in.if your amp dosnt have enough capacitance ...its a shity and amp and you should takeit back to 1986 were you got it from becasue thats about the last time caps were usful,but if you want you can use a cap, it will help you amp, but it dose not fix real problem. )
whats the real fix you ask? Upgrade your cars electcial system ,upgrade the cars wireing ,the alt to batt wire is normaly tiny about 10g...upgrade it to 8g or 4g if you can, and upgrade the grounds, loosen a bolt that holds the alt and make a ground form the frame of the car to that bolt , normaly engines arent grounded all that well since there held to car with rubber mounts and the factory grounds are added as needed and are tiny ... and make a better batt to chaisse ground if needed.
(idk about ours cars i have yet install a system in one yet, im not sure how its all set up since our batt is in the trunk)
If you know for a fact your car has a beefy alt(our cars somthing like 140amp) yet you lights dim try doing the above first, I have fixed many light dimming problems just by upgradeing the wireing... in cases with large systens its a good idea to upgrade to a highout put alt. (200+amps) only then would i reconmend extra batts , and for any one with a system i recomend a optma yellow top with the light grey caseing, its a deep cycle battry that can be used for starting,and since its a deep cycle it means you can drain it to point of almost being dead and it will always return to a full charge. and its the only batt that has a Warranty if you have a full system or other things like air ride and such...
i to worked at cicirut city (3yrs) i tried my best to not sell caps for the reson of dimming lights . (uness we were close to budget anb i neded the extra install pointsLOL)
heres why adding caps and extra batts to a stock electcal system is a bad idea.
amps dont make power they convert it .
if you have 1000wrms amp it dosnt just pull that power out of no were .you car has to be able to make 1000watts ,
(this is a extrem example of what not to do)
most cars run at about 13.9v when running lets say you have a civic dx with an alt. that makes about 60-70amps at full tilt.
so you take your civic and you put a big phatnacky system in it (2)1000wrms amps ,big 500wrm 4ch and just for shiggles some neons and stuff...it all gets hooked and ...wow you light now dim when the bass hit...wonder why? lets find out how much crrunt you are drawing from your cars charging system... divide your systems rms by your cars voltage 2500w/13.8v ...wow your trying to pull 181 amps from an system that only makes 70amps...so what happens when your alt cant deal whith the load , it truns to the cars battry. now your thinking no prob my batt is like 700cca (cold cranking amps) it can hadle the crurrnt draw...it can but only for a few mins..lol batts take a long time to recharge. and since your alredy drawing more current then the alt can supply your now draning your batt quicker than it can recharge. at this point most people just see there lights dim and throw a cap on there system...fixes the light dimming for while, but now you just put more stress on the charging system, not only is you alt tyring to keep the batt charged and the car running , its got a new job of trying to keep the cap charged aswell ,this is also why throwing another batt in is a bad idea too. .So what happens next? most likely your alt says screw this i quit...your batt soon follows and now your stuck on the side of the road becasue you put more strain on your cars elec.system than it was ever desinged to handle. (all a cap dose is store engery ,and guess what ,pull your amp apart.. its full of caps ,if its well made it alredy got all the capacitance it needs built in.if your amp dosnt have enough capacitance ...its a shity and amp and you should takeit back to 1986 were you got it from becasue thats about the last time caps were usful,but if you want you can use a cap, it will help you amp, but it dose not fix real problem. )
whats the real fix you ask? Upgrade your cars electcial system ,upgrade the cars wireing ,the alt to batt wire is normaly tiny about 10g...upgrade it to 8g or 4g if you can, and upgrade the grounds, loosen a bolt that holds the alt and make a ground form the frame of the car to that bolt , normaly engines arent grounded all that well since there held to car with rubber mounts and the factory grounds are added as needed and are tiny ... and make a better batt to chaisse ground if needed.
(idk about ours cars i have yet install a system in one yet, im not sure how its all set up since our batt is in the trunk)
If you know for a fact your car has a beefy alt(our cars somthing like 140amp) yet you lights dim try doing the above first, I have fixed many light dimming problems just by upgradeing the wireing... in cases with large systens its a good idea to upgrade to a highout put alt. (200+amps) only then would i reconmend extra batts , and for any one with a system i recomend a optma yellow top with the light grey caseing, its a deep cycle battry that can be used for starting,and since its a deep cycle it means you can drain it to point of almost being dead and it will always return to a full charge. and its the only batt that has a Warranty if you have a full system or other things like air ride and such...
08-29-2007, 11:24 AM
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08-29-2007, 12:06 PM
#31
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and be for i get flamed or waht ever, id just like to say, caps do work, they stop voltage spikes/lights dimming. and help the amp preform better,but its not a fix to the real problem.
If your lights dim whats the problem? Answer: not enough engery. What dose a cap do Answer:stores engery, now dose that fix our proeblem...no,it covers it up.
its like getting shot and putting a bandaid on it .
If your lights dim whats the problem? Answer: not enough engery. What dose a cap do Answer:stores engery, now dose that fix our proeblem...no,it covers it up.
its like getting shot and putting a bandaid on it .
08-29-2007, 12:42 PM
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Caps are semi-useless... If you have a larger batter and alternator... =/
<200 for huge cap
>300 for alt/bat
its all in how u want to do your stereo...personally i have a 2f cap for my 1k amp and its just fine for me... id like to get a larger alt and redcap bat though. For spikes they are fine, but you should really get a larger alternator so u dont blow out some **** in your alt. happened to me twice. 2k watts rms and two 15"s on a stock alt is not a good idea..
<200 for huge cap
>300 for alt/bat
its all in how u want to do your stereo...personally i have a 2f cap for my 1k amp and its just fine for me... id like to get a larger alt and redcap bat though. For spikes they are fine, but you should really get a larger alternator so u dont blow out some **** in your alt. happened to me twice. 2k watts rms and two 15"s on a stock alt is not a good idea..
08-29-2007, 12:48 PM
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after reading that I am sort of skeptikal because like many I had a competition setup and the cap has stopped my lights from dimming everytime, but extra batteries always solve the problem.
08-30-2007, 05:49 AM
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08-30-2007, 11:21 AM
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Wow this thread is out of hand. I am an electrical engineer, and
A) The link is complete BS the guy doesn't have a clue what hes talking about. He thinks that the ESR of a 1 Farad cap will be the same a bigger cap. When the cap gets bigger the ESR goes down, its the only way to make the cap work in the first place.
B) Caps help stiffen the voltage rails by adding the 20-40amps needed when a big bass boom hits and thats its, after that it has to recharge, that takes approx 50ms then its ready for another big boom. This keeps the lights from dimming in 2 ways, 1 it provides the necessary amperage at 14.4 or 13.9 depending on what the alternator was running at, it also helps for that millisecond that the alternator needs to increase its load. Alternators do not run at full tilt all the time, if they did they would burn out in no time flat. The sensors that adjust the field windings cant compensate for the bass boom instantly so the lights dim as you go from 14.4 on the alt to 12.6 on the battery, and if its a big boom, the 10.5v or so that a loaded battery puts out.
C) Now that we know all they do is stiffen voltage rails you have to look at what they can be used for, if you have a system that consistently draws over what your alternator can put out at peak, it wont do anything, thats pretty rudimentary. Now if you have a system like most where the highs maybe draw 20amps at peak (good for ~250RMS Watts) more than enough for highs, and a bass boom that hits with 60 amps (~700RMS) then the cap only has to fill in those little gaps when the bass hits, the alternator can cover the highs easily and should be able to give off in the case of a 120amp alt around 40 to the subs so all the cap has to do is provide 40amps for the 5ms or whatnot that the bass hits. This power is then provided at 14.4volts, which keeps the system from going into the batteries hard which would drop the voltage down to 10.5V or so. The light dim is really only noticeable when you go from 14 to 10 quickly.
Also just for the record, we have crappy alternators, I think they ar 115 for the 2.2, 2.4s and 135 for the SS's
A) The link is complete BS the guy doesn't have a clue what hes talking about. He thinks that the ESR of a 1 Farad cap will be the same a bigger cap. When the cap gets bigger the ESR goes down, its the only way to make the cap work in the first place.
B) Caps help stiffen the voltage rails by adding the 20-40amps needed when a big bass boom hits and thats its, after that it has to recharge, that takes approx 50ms then its ready for another big boom. This keeps the lights from dimming in 2 ways, 1 it provides the necessary amperage at 14.4 or 13.9 depending on what the alternator was running at, it also helps for that millisecond that the alternator needs to increase its load. Alternators do not run at full tilt all the time, if they did they would burn out in no time flat. The sensors that adjust the field windings cant compensate for the bass boom instantly so the lights dim as you go from 14.4 on the alt to 12.6 on the battery, and if its a big boom, the 10.5v or so that a loaded battery puts out.
C) Now that we know all they do is stiffen voltage rails you have to look at what they can be used for, if you have a system that consistently draws over what your alternator can put out at peak, it wont do anything, thats pretty rudimentary. Now if you have a system like most where the highs maybe draw 20amps at peak (good for ~250RMS Watts) more than enough for highs, and a bass boom that hits with 60 amps (~700RMS) then the cap only has to fill in those little gaps when the bass hits, the alternator can cover the highs easily and should be able to give off in the case of a 120amp alt around 40 to the subs so all the cap has to do is provide 40amps for the 5ms or whatnot that the bass hits. This power is then provided at 14.4volts, which keeps the system from going into the batteries hard which would drop the voltage down to 10.5V or so. The light dim is really only noticeable when you go from 14 to 10 quickly.
Also just for the record, we have crappy alternators, I think they ar 115 for the 2.2, 2.4s and 135 for the SS's
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