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how to wire a capacitor....

684 Views 13 Replies 5 Participants Last post by  Craig King
Ive never seen one out of it package but how hard are they to wire?

edit: Like does it go before the amp or after the amp wireing??
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the positive terminal of the cap taps into the power wire between the battery and the amp, but as close to the amp as possible. it's easy. the cap comes with decent instructions, at least mine did.
you also should need to ground the capacitor at the same point on the car that you ground the amps:)
So can i throw one in in like 5-10?
I dont know if i need one yet and i probably wont cause im not running to much power (~800watts)..
thanks alot for your help
You will need to charge it up first. After that, it shouldnt take any more than 5-10 minutes with the right tools and wiring.

Why would it need to be "charged up"? It's not a battery - it's a capacitor and if he charges it up before installing he's liable to get a shock. Why wouldnt it simply charge up when he turns on power to the amp the first time? :confused:
A cap kinda is a battery.. But what it does is store energy and has a very little resistance.. what the amp needs alot of juice it sucks it from the capasiter where it can get all the energy it needs fast other than trying to suck it all the way through your wire from the battery.

people use them alot if their lights dim on hard bass with alot of power, But its only a cheap fix. If this problem persists you need to look at upgrading your alt.
A cap kinda is a battery..
not kinda, it is a battery...... a capacitor stores energy, so by definition it is a battery.

I have (2) 1 farad RF caps on my install... i'm running a power1100a2 and 3 JL 12's in my other car, and i've competed with it and i think the caps have saved my alternator and help me maintain power through competitions. I would definitly reccomend a capacitor when running and system that is powering subs, or where more than 500 watts is being produced where they are constantly drawing stupid power to play loud.

and yes, the cap has to be charged.. it's quite simple, you simply use a resistor, (usually comes with each cap) and it's used to help charge the cap for the first time. it's placed as a connection between your battery and the cap, and it's only needed once, as you will effectivily fry it when doing so...... but that means it worked.

be careful with caps too.... just remember that they are just as "live" as a battery and they well whack you pretty good if you cross the terminals
I understand how a cap works - especially the electrolytic ones whish is what I believe are used in amp installs bu tI still don't understand why they must be charged. As soon as your amp has power applied the cap ought to charge - amp turn on migh tbe delayed but no biggie. For that matter - doesn't it discharge when the amps are turned off? Is it wired in series with the amp's power wire or what? I guess I'm just not picturing this...
BLKMGK said:
For that matter - doesn't it discharge when the amps are turned off?

No, it always has stored power in it. As soon as you charge it, it will always be storing power. the whole point of a cap is to provide the extra juice to keep your alternator drawing away from other accessories(i.e. HEADLIGHTS!)
I know how cap works

It's there for on demand power surges. However when you shut the car off does it not still provide power to the amp? Ever seen a a stereo where when you turn it off the lights dim slowly? Those are caps in the power supply draining off. When you turn it back on they charge right back up and are ready for use. If a cap is wired in series on say the hot wire this is the effect you would get. Having not used a big cap in a stereo application I'm not sure how they'e being wired but if it's series on the power wire they will drain each time power is removed unless there's circuitry built to prevent this...
you need to charge the cap because if you don't it will draw a lot of current at once to charge the cap. Kinda like a dam breaking.. you don't wan to do that.. can blow up cap. Use a test light to charge the cap. hook the ground side up first and with the test light clip to postive of battery, probe the postive with test light. when the light goes out, cap is charge.. safe and easy.. just don't cross the two terminals.. or big boom!!! very fun if you like to scare people.
That makes more sense

If the power draw of charging the cap is going to fry things the first time, like a dead short would, then this makes MUCH more sense.... Thanks for the explanation!
Re: That makes more sense

BLKMGK said:
If th epower draw of charging the cap is going to fry things the first time, like a dead short would, then this makes MUCH more sense.... Thanks fo rth eexplanation!
drinking and wiring capacitors is not recommended
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