Capacitors

[GP99GT]

my friend needs a capacitor for his mustang, so im trying to figure out what to get. i know a little bit about them, but wtf is a 24 volt capacitor? and how does it work with a 12v system?

[qwikz28]

its a max rating

[project89]

if hes just buying a cap cause the lights dim or he keeps killing his battery,the cap wont do any good. and u need a .5 farad cap for every 1,000 watts the amp pushes.so if he has say a 100-1000 watt amp he dosent need anything more then a .5 farad.most places will try to sell u something much bigger.and be carefull when u charge the cap for the first time if u do it without the resitor the cap can explode in ur hands/face.and after its installed if ya ever work on the amp cables or around the cap take the fuse out of the power cable and short the 2 terminals of the cap with a junk screwdriver or something.u do not want to get zaped by a capacator.besides hurting really bad and cauising sever elc burns.most store enough to kill u

[GP99GT]

yeah ive installed one before in my own car, but i never really paid attention to this 24v thing. hes getting it because, well his headlights dim, and his alternator is only 70amp i think. pretty weak. already blew up a 4 month old alternator, we arent sure if the stereo was the cause of it but were gonna disconnect it for now til he gets a cap.

[project89]

what size amplifier? a cap is not going to help the dimming lights,once u drian the cap u still have to recharge it using the batt/alt.what he really needs is an upgraded alt

[GP99GT]

its only like a 1000 watt amp...probably 350 per channel

[project89]

what brand? my alpine amp 400 watts rms 800 peak pulled 45amps at max power output.yeah he wont need anyhtng more then a .5 farad cap

[qwikz28]

capacitor = bandaid
hi output alternator = solution

[project89]

capacitor = bandaid
hi output alternator = solution
it isnt even really a bandaid.installing a second batt is more of a baindaid then a cap.

[qwikz28]

i think a second battery would help more then a cap. at least for a show car.

if your car has a well built electrical system, (i.e. hi output alternator, a good battery, upgraded wires) you wont need a cap or a second battery for that matter. my alternator is about to take a **** on me so i'll soon be ordering a nice high output one and i'll then ditch my cap and even get bigger amps :twisted:

hey dave- next time i see you i wanna give you a quick rundown on what i plan on changing in my system and see what you think. i'm kinda iffy about it and i'm not sure how it will do. [/hijack]

[project89]

what ya got now and what changes do u want to make.actually start a new thread to keep this one from getting hijacked to badly.lol

[V]

hmm i never used a cap and i will never either.

[project89]

i dont use them until i get upto around 4,000+ watts then ill install a few,but there is no reason to use one on a basic system,hell battery's /altanators have goten so good,that even most competition viechals dont use caps anymore

[qwikz28]

my isuzu didnt need a cap when i had the 1400 watt JBL at full blast. not even the slightest dim of lights on the factory alternator at 90k miles with a crap interstate battery. i miss that car :(

[LT!freak94]

ok i diddent know you had to charge the cap i just put it in and thought that was it how do you go about chargin itand how long i dont know what kind i got i like it though cuz it has like the digital readin on it its like a i dunno i got it at advanced with the kit they sell

[project89]

the cap should have come with a lil resistor.what u do is hook up the ground,then u put the one end of the resitor onto the positive side of the cap,and the free end goes to the cable comming from the battery.the time it takes for the cap to charge varys according to manufacturer.read the directions that came with it and it should tell u.and treat that cap like a live grenade.i have seen first hand what happens when the explode,and its not pretty. and the cap from advance its more then likely junk to start with.what brand is it?

[97Formula]

Ok, I have a few questions regarding capacitors as well.

I've had one for over 5 years now, do these things go bad after a while?

Also, do I still need one with my KAC-8101D sub amp (Class D, 400 watts x 1 at 2 ohms)? Reason for this question is because I heard Class D does not draw as much current as older amps (it does have a 40 amp fuse however).

I had this with one of my older amps and I think it helped a little with dimming lights and slightly better bass. But, it seems today that most are saying caps are useless.

[chevylover5]

no caps are not usless, i have 2 10in pioneers and a mono 750watt amp. they are matched and sound beautifully, but the lights used to dim when the system was cranked. so i put a 110amp alt on it and it made a difference, but it still dimmed when at traffic lights. so i put a .5 farad cap on it and it works like a dream... caution tho, the first time i used the cap i blew my electronic ignition, it was working and it blew 2 fuses then i was driving and it did it one day and my lights went out and it stalled. electronic ignition was blown, had to tow her home. i found out the + & - cables had play in them and were hitting against eachother. and FYI it does hurt like a biznitch when you get shocked by even a .5 farad cap. but its all fixed now and i found out the were loose because they were stripped and i had to drill and tap 1/4 20 bolts in there. but all is well and i do recommend having a cap on her.

[V]

i never used a cap nor will I, it really comes down to personal preference and opinion.

edit: wow, i almost typed exactly what i said when this thread was new, almost a year ago.

[97Formula]

capacitor = bandaid
hi output alternator = solution

Hmmm, starting to believe this. I took my cap out only to find out that the headlights were not dimming any worse without the cap (the only time the lights dimmed and the voltmeter goes down is when the car is at idle, and all the lights are on, only slightly better with the cap). The volts don't go down at all when the headlights are off (with or without cap).

My alternator is the stock 140 amp, and as long as I'm doing better than 1000 rpm, the headlights don't dim, and the voltmeter doesn't move (this is without the cap too). What needs to happen in order for this to not happen at idle?