capacitor test

[walight01]

as a side note on batteries, if you have more than one battery, it is a GOOD idea to have 2 of the SAME batteries.

[walight01]

Originally posted by demoninvictus
damn that sucks... can you still justify a deep cycle battery ? i was skeptical of stiffening caps, not for any particular reason, but what if anything is there you can do? is running multiple batteries going to help out? and also, if you run 2 batteries, how does your electrical system compensate for 2 batteries? are our car's electrical systems still able to regulate the voltage better with two batteries, or is that just better for competitions when you have to expect that your car will be off for testing?
peace

2 batteries give alot more reserve power to help out the system when it needs it.so as long as the car is running and the 2 battiers don't constantly discharge it will help, now if the alt is having to feed your amps(which it already can't do by itself,) and then it tries to recharge the batteries at the same time, then yes there would be problems. from what i understand, you can have your car running during comps.

[blue LEDz]

Originally posted by walight01
as a side note on batteries, if you have more than one battery, it is a GOOD idea to have 2 of the SAME batteries.

yep, but damnit i'm cheap oh well. i have to get 2 new ones anyways, so 2 spiral cells it is:p:

[walight01]

well there is a difference between being "cheap" and not just not being able to afford it

[MisterT]

I had to read the article again!! 15 farad cap and no difference?!?! A can see the pros and cons of a cap in that it can strain the alternator and yet it can help with dimming. If I should go with a 2nd battery, what are the procedures of installing it? Will one drain the other? Is that what an isolator is for? I am clueless to this type of set up. I have never had the means to use one, but if it's an alternative to help with lights dimming, then it's something worth looking in to. Otherwise, I am going to learn some thing new which is always a plus.

I tried emailing the guy who sold me the kickpanels on SoundDomain but haven't heard from him. He is also on msprotege, but I haven't seen him in months! I wanted to see what he did with his set up. He used a JL 1000/1 and a 450/4 and went with a SVR50-12 and SVR28-12 along (isolator of course) with a Alumapro 15 farad cap!! On top of that he has Head Unit, LCD, PS2, two JL 12w6v2, Boston Acoustics Z6 and Neo 5T Ambient tweeters!!! That is a lot of ****! 1st MP3 thinks he is using the stock alternator, although he did run 1/0 gauge to it from the batteries and used 1/0 gauge througout the entire system. I should hope that all of that took the dim out, but is that overstraining that alternator if stock????

Sorry for long post.

[blue LEDz]

from all that i have read, when you install a second battery, they each need exactly the same length of wires from the isolator or alternator. differences in resistance can burn up one or both of the batteries over a long period of time. also the internal resistance has to be pretty much identical, otherwise it has the same resistance problem, and will eventually die. misterT, you are not running enough power to need a second battery. as long as the voltage stays above 12.7 volts, there is no need for it. my voltage was dropping into the 12.3 volt range, which is why i got a second battery. too bad the one in the trunk wasn't as well built as the spiral cell up front, cause when i took the battery out, i could feel the plate move inside the battery there is the other problem with a 2 battery setup. my one battery killed the other so now i can either replace both, or just get one really good one up front, which is what i plan on doing. less space taken up in the trunk, and less hassle

[MisterT]

Originally posted by blue LEDz
misterT, you are not running enough power to need a second battery. as long as the voltage stays above 12.7 volts, there is no need for it.

I just was thinking maybe it would help with the dimming, but I guess not If I went with a Tsunami amp (1100 watt one) would I be in the same vote as my less powerful, but very inefficient SoundStream? I say Tsunami because it is $50 cheaper than the 800 watt Avionixx. Either one of the amps (Tsunami or Avionixx) would probably do me trouble with the dimming because of the power output. Lastly, I wish I had discovered knukonceptz with the power wire running to my amps. After using their wire for the groundkit and wiring to the alt., they are so much better quality than the LA ****. I can cut the LA **** with a pair of wire cutters (used to cut standard fence wires) and with the knu wires, I have to use a good size knife to cut them!

[blue LEDz]

yeah, i love knukoncepts wire. it's great, and so is the price i personally don't see a need to get over a 600 watt amp, but if you do, just turn the gain down a little, and you'll get less power, end better efficiency either the tsunami or avionnixx would be a good choice, cause then you do have the power on demand does either come with a remote gain control? you can use that to adjust the gain down a bit from up front, in case there is dimming, but then you can crank the knob up for full power, where the gain is set on the amp

[walight01]

i was just pondering this idea on the cap test, he used a 15 farad cap on a 2k watt system when it only needs a 2 farad cap. whats the esr on a 15 farad cap compared to a 2 farad cap?? i mean a 300 watt amp can run for about 2 sec at normal playing levels on a .5 farad cap and takes no time to recharge. so i'm just wondering if he would used a lower farad cap if it would have made the results any different.

[blue LEDz]

while it is going to be a little different for a lower powered system, the test was mainly showing that if your alternator can't produce enough power, a cap will not help.
take a 300 watt amp for example, say it needs 400 watt intake, cause it's 75% efficent. say at the amp we get 13.5 volts. it would take 30 amps to run the amp at full power all the time. but we know that the amp doesn't run at full power, unless all you do is play sine waves through it and we'll say our alternators have 20 extra amps over what is needed for the car. then that leaves 10 amps extra draw. so we've got a .5 farad cap hooked up. once the voltage drops to 12.8 volts, a capacitor is worthless, since the battery is supplying the current. now we use the formula for capacitance:
capacitance = (change in time X current)/change in voltage.
.5 = (change in time X 10 amps) / .7 volts
the change in time that the capacitor is actually useful is only .035 seconds not a whole lot, now is it?
so now let's use 2 farad on 2,000 watts of class D power.
we'll say the amps are 85% efficent, so they need about 2353 watts input. at 13.5 volts, that's almost 175 amps and with only 20 amps coming from the alt, let's look again at the formula:
2 = (change in time X 155 amps) / .7 volts
that's even less time, and only .009 seconds
now use the 15 farad one:
15 = (change in time X 155) / .7
.0677 seconds. still not a lot of time
so unless your alternator can supply almost all the power for the amp, a cap is worthless
just for ****s and giggles, let's do it with a 100 farad cap:
100 = (change in time X 155) / .7
time = .4516 seconds getting there, but still not great

[walight01]

i know what the test was proving, i was just wondering if it would have made a voltage difference, but i didn't think about 175 amps of pull, so i guess the only thing that could help is a 200 amp alt or a half a dozen batteries(assuming he is only gonna play the system until his batteries drain.

[MisterT]

Okay, dumb question here for you. If that is the case, then someone in my situation doing the electrical system of the car worse by using a 1.5 farad cap when dimming is still occuring. I mean, it seemed to help, but slightly was what I discovered, but now I am wondering if it is partly psychological and that the cap is drawing current from the battery as well as the amps, adding more unnecessary stress to the car's electrical system. Perhaps I should take the cap out of the equation. I wish they did a test too on a smaller system (like 1000 watts with a smaller cap like Walight said. Before the dimming problems in the Protege, I had no dimming problems in previous installs and the equipment including the cap sat in a box for 2 years!! It would be interesting to see if a new 1.0 farad cap would keep it from dimming because the cap I have now may have gone bad. I guess I just have to some how meter it.

Too bad I couldn't go to a shop and have them install one to see if it worked and if it did, I could pay for the new cap, and if not, then they wouldn't charge me for a new cap.

[blue LEDz]

in most cases of smaller systems, a cap just slows down the light dimming, so it doesn't happen as fast it gives the visualization it helps, but does nothing for the stereo itself i'll see if my friend still has his 1 farad stinger or LA cap laying around. it did nothing for his system, which is my old system:p: but if you cap is bad, and you are right near the limit on your alt, the 1 farad will cover up the headlight dimming or we could still try to put one of my 1/2 farad caps inline with your fuse box, and see how that works if it works, the cap is your's, free of charge (my 1/2 farad, not my friend's 1 farad )

[MisterT]

I am juggling between dealing with the dim, but will take it on another test run and getting the amp from Rider. Problem with the cap is where to mount it under the hood and keeping it from getting overheated. Just seems like with the dimming, it can cause harm from to the car's electrical system whether it be the battery or alternator.
I say another test run because the cap is out (1st time since before wiring 4 gauge wire to the alternator). No expectations though. Don't want to get disappointed, but it does still dim, maybe not as badly. Maybe I am in loser denial! :p:

[blue LEDz]

a better test of it would be with a voltage meter, not just by your seeing the headlights dim i got the wrong meter at sears, and have to get the right one, then i'll run a full test when i bring you the new box

beer = bad typing, and a lot of backspaces to correct