I'm no new comer to the car audio scene.....but I've never owned a system that needs an alternator upgrade.
My question is if you get a large enough cap, like a 20 farad, would you need to upgrade your alternator?
I know that caps are like reservoirs of power so with a large enough cap, and you not playing your system at 100% for hours at a time to give the alternator a chance to recharge the cap, would a large cap do the trick?
Someone let me know....
If you need my system specs I will post them....
I have heard two different things regarding caps.
I heard that it's 1 Farad per every 1000watts of power but I recently heard it's more like 1 Farad to 200watts of power....
I understand the concept of a cap and I know some say it is like a bandaid to a permanent problem but I need an answer to my question.
Thanks,
Austin

 

unfortunately if you are running a large system you may wnat to consider a alt upgrade. or upgrade your batt and get maybe a 5 farad cap, depends on your specs.
What are you running?

 

IMO change the battery to a deepcycle one 1st

 

caps are good for short duration bursts. But it depends on what power levels you are running. Even if you do not experience light dimming when running at high levels, you need to look at the rating of the alternator in comparison to what you are adding.

Power = VI (I equals current). So if on your amp output you are producing 500 watts, lets say, then your charging system has to make 500W/14V = 35 extra Amps than normal. With the stock alternator (which is 95 amp rated I believe) that is going to start working it pretty hard. Even with a cap, the alternator has to supply all of the current needed to recharge the battery and cap. But... if your amp is rated 500w peak, then you can expect it to realistically be able to produce around 250 - 300w rms, and this is only for short bursts of time. Amps manufacturers usually rate in peak power for short duration. So you are actually producing much less average power. In my other vehicle, with an 80amp alternator, I have run a 600watt amp (and I push it fairly hard) for 2 years with no issues with the alternator. I know this does not give you any specific results, but hopefully it will get you started. It really depends on how much power you are using and the application. One thing to remember though, every bit of power taken from the battery has to be supplied back by the alternator, which means if you are using 50 more amps with an amplifier, the alternator has to be capable of supplying that regardless of the capacitor and battery setup. So always make sure the alternator is rated to supply the cars electrical systems current draw and the total rms draw of your sound system. I usually try not to go over 85 - 90% of the alternators capacity just to be safe. And you should figure this with the heater, lights etc on the car turned on to cover your bases. It helps if you have a good ammeter to determine how much total current you are drawing from the system. That way you will know for sure. Usually it is easier to find an inductive type clamp probe that is rated high enough for this. Then you just clamp around your bat cable, turn everything on, crank up that system, and know for sure what you are drawing. Then size everyting else accordingly. Ok , this is long... but hope it get s you started. I'm a tech geek and tend to go on and on about this stuff

 

You need to upgrade the electrical system first. High output alternator, optima or a dry cell battery, the Cap is only for musical sound quality, the cap will act as a storage device, to provide instantinious power, or dynamic headroom, so the amplifier wont clip. It DOES NOT help the charging system, capacitors are not an instant cure all for your cars electrical system. Bill

 

Ok,
My system will pull 2520watts RMS:
2000watts Eclipse DA7232
260watts Eclipse PA4212
260watts Eclipse PA4212

Note that is RMS! The peak is 5240watts:
4000watts Eclipse DA7232
620watts Eclipse PA4212
620watts Eclipse PA4212

Our alternators are rated stock at 80amps.
My amplifiers alone can pull:
200amps peak Eclipse DA7232
50amps peak Eclipse PA4212
50amps peak Eclipse PA4212

300amps total just from my amps (not including other electrical components).

Now what you are saying is that a cap is made to supply the amps for short burst of quick energy that in needs. I got that.....

What I don't really get is a massive 20 farad cap....are they made for 20,000watt systems?

So the cap isn't really like a extra storage tank then?
Lets say that I have my 2500watt system and I get the alternator upgrade and I get a 5 farad cap.
I when the system slams the cap will provide the amps with the power that it needs as soon as it needs it because the battery itself cannot provide the power as quick as the amp demands.....?

Am I reasoning right?

 

your alternator will need to be able to supply at least that much plus the normal load of your system, plus a margin of safety.... you need a huge alternator in other words.

And as a side note... caps are not only for sound quality. They will prevent minor dimming of the lights. Caps are naturally high pass filters. A super big cap, which 1 farad or above is in electronics terms, is a high pass filter with a fairly low cutoff frequency. So any spurious dips in the line voltage (during short peaks from the amplifier which normally causes lights dimming and amplifier clipping due to spiked voltage drops) are actaully filtered to ground via the capacitor, which is actually how it prevents the occurence of the lights dimming. Think of the spikes as high freuency signals when compare to the 0Hz of the DC power line. So if all a person is trying to fight is a "flickered" dimming of the headlights, a capacitor will do the trick. But your system is definitely serious business and will need battery upgrades as well as alternator upgrades.

 

every one is most likely correct in needing a new alternator, but if you really don't want to do that then maybe you might just wanna try getting a new battery and upgrading your big 3, then if that still istn't really cutting it (which it probably wont) then you should get a new alternator. by the way what are you running with all those amps?

 

Oh.. and yes, a capacitor is in a sense like a storage tank. It is a battery with a short lived charge. They are similar to a battery in that way. In one way you can see that the storage capability of the cap is "holding" the line voltage during high current spikes, but cannot sustain it long enough for longer duration drains. This is described technically by the filtering effect of the cap. Hope all this helps.... and add some pics when that system is installed! sounds nice!

 

but let me remind you that in order for the alternator to sustain charge to the battery, it must be capable of supplying the entire current draw of the system. if not, the alternator will die (very soon with the amount of overload you are talking about) and the battery will drain even with the engine running.

 

Caps, bleh. With that much power your need an alternator. If not then downgrade your systtem UNLESS you keep the volume down....

Gotta pay to play, or pay for a new alternator like I did. I had a 1400 watt PPI and 300 watt Orion and it killed my ~130 amp Accord alternator, FAST.

 

I agree totally. Like I said, caps are good for smoothing out very short spikes (and I mean in the mS range) , nothing more.

On another note, how did you like the PPI?

 

you could also run more than one battary, along with a not so much of a big ___ alt.

 

The alternator has to produce all the power used regardless of the number of batteries.

 

PPI went BAM! POW! SHATTER!

I think it died at the same time as the alternator. I actually had two of the Chrome PPI PC21400s. Ran it @ 2 ohms for a bit too, I guess 2800 watts to a 15w3. Box was sitting on the floor of the garae and started dancing the salsa.

Also hooked them up to some components and it sounded great. Running some Arts now and they're great too. Would run their new stuff but JL stole the design team. o wells

 

I thought they got there slash series from the old xtant guys..?!

 

____ thats a system, You definately need a 140amp alt with a deepcycle.
I would seriously considering rethinking your choice. Are you compeating??

 

i have two of my big three upgraded( block to frame, batt - to body), 1 farad cap, and a yellow top optima and my xb dims like a *****. i have competed and plan on competeing more this year and plan on upgrading my system again, so i am guessing an alt upgrade and another battery would be suited for me.

 

DOn't get fancy try a Jacobs Accuvolt

 

ive had the same system set up in the last three cars ive owned... no problems. I'm running a Rockford Fosgate Power500bd mono on my Alpine Type R 12", and a PPI power class 500watt two channel on my front components, 4 guage wiring, no capacitor. My voltmeter on my Escort 3500 stays at 12.5-13.4 consistantly.