I pay 100 bux for a .5 farad capacitor last september and people are saying on the site that they die after a year. It never did much to begin with, and people said it would help, but what I wanna know is how long do they last, I've heard a year, i've heard longer, what is it?

 

A cap will last longer then a year as long as its not abused (like constantly being shorted out or letting it get hot enough to leak).

 

well 0.5F is pretty much useless....1F sorta helps some of the time (depending on your cars electrical system, system demands ect).

If your having voltage problems look for the problem, not apply a bandaid (the capacitor).

 

.5 farad is plenty unless you've got a huge system. The old rule of thumb was 1.0 farad for every 1000 rms watts, but most amps have a ton of capacitors built-in, so you don't need as large of an external cap as in years past.

And they last a lot longer than a year. Unless you abuse the sh*t out of it or short out the terminals, it'll last for years.

 

The only way a cap would go bad would be to charge it incorectly (which with most model releases a liquid which breaks the cicuit), or two drop it (break the glass). Caps rely on a large piece of glass with oppositely charged electrons on either side. They most take alot of damage and work to prevent it from working. They will last alot longer than a year. I have had mine for over 8 years now running 1.5 farads (1500 watts) on a 1200 watts system.

 

Blibby69, some info for you and every one else on this subject. Capacitors are made up of two plates (conductive) separated by a dielectric (non-conductive) material. Caps can and do go bad for other reasons than that. They don’t have glass in them; not the type used in car audio any way. The ones we use in the cars are electrolytic capacitors, the dielectric material is more like wax paper that is wet, but it’s not wax paper. The “wet” is an electrolyte liquid. In high heat or over the years this liquid will dry out. The lower the heat the longer it will take to dry out, like 100 years or more for a good quality cap at room temp. At one for my old jobs we refurbished old amps in jukeboxes and those caps used wax, real wax, that as it aged would leak out and the cap would be leaky, not just because they where leaking the wax but they would also “leak” current. Some caps do use glass but they are more for extreme high voltage uses, some thing like over 10,000 volts and only vary low values like 2 to 10 pF which is 0.000000000002 farad or something like that. When you drop an electrolytic cap you can dent it, BAD, or you can damage the dielectric, the “wax paper”. As far as charging the cap goes, the polarity MUST be observed on electrolytic caps (most of the time). If you do a fast charge or short it out when it has a charge what happens is the plate will get real hot for micro seconds, HEAT BAD. Doing this over and over again will “dry out” the cap. Its also good to note that saying the cap is leaky doesn’t always mean that it is leaking the electrolyte, it could be “leaking current”. When a cap is “leaky” it could still allow current to flow when charged or the value of the cap will go down. Well that’s my dissertation on SOME of the things that can go wrong with caps.