What is the point? I spent $155 for a Stinger 1 farad capacitor that was supposivley top of the line, yet now I sit with a dead alternator... why did this happen?

 

what do you mean by a dead alternator? What do you think the capaciter does?

 

Do you mean a dead battery

a Capacitor stores energy and its discharged when that energy is needed. then recharges again.

I dont see how it can kill anything.

 

He's saying his alternator died because the cap was not doing it's job. A cap takes the strain off the alternator when an amp requires a large (or even small) amount of power. If you don't have a cap and the alternator is handling it's normal load in addition to an amp, there's a good chance the alternator will crap out. Especially if you have a smaller alternator (100 amp).

First, I would check your cap and make sure it still has power. It's probably dead now but charge it up and see if it holds the charge while in use. A voltage meter for the cap is always a good idea. That way you can tell if it's recharging after heavy loads.

Also it may be time to get a bigger alternator. You shouldn't have any problems if you convert to a 120 or 140 amp alternator.

 

what alternators would you suggest in the 120-140 amp range?

 

My system drawas peaks of 125-150 from the vehicles elictrical system and have had no problems since the installation in 1986 in my Grand National........shitty gm delco alternator....

 

Don't know. I've never had to buy one. You need to do some troubleshooting to make sure that's the problem first. Higher performance alternators can be pricey. I'm sure a local sound or speed shop can help you find a high amp altenator if that's the problem.

 

God, I wish I had known a few years ago, that thousands of gullible audiophiles around the country would actually pay $155 for a capicitor.

I would have retired years ago...

 

You nailed it on the head, I wasnt blaiming the cap I was simply saying it wasnt doing its job. it has the Digital volt meter and its cleary holds its charge.... either way im still out another 250 bucks for a new alt!

 

I have a stereo with two caps because i knew that my amps were pulling a lot more amperes than the alternator would give even at below capacity. Who ever said just one farad cap would do the job? Plus with bigger amps you should run a dual battery system to be on the safe side. Car audio will never be 100% and it never has. My civic alternator has been replaced twice but was warrantied because i used dual batteries and an isolator. You car is "6" car years old, not bad if you have been running a system a while on the original alternator. Go to a good sound place and maybe even two for advice. Maybe an upgrade will be unneccessary and you can save that money and add another farad or battery! Good luck!

 

To put things in perspective, the big caps can smooth out power peaks, but wouldn’t do $hit for the drain on the alternator (this being the average RMS current being drawn from your power amps).

The energy in a 1 farad cap would be (1 Farad * (12 volts) ^2)/2 or about 72 watt-seconds. (That's 72 watts for a 1 second)

Looking at this another way (from "How things work"):

"To get some perspective on how big a farad is, think about this. A typical alkaline AA battery holds about 2.8 amp-hours (see this page for a chart). That means that the battery can produce 2.8 amps for an hour at 1.5 volts (about 4.2 watt-hours -- a AA battery can light a 4-watt bulb for a little more than an hour). Let's call it 1 volt to make the math easier. To store that much energy in a capacitor, you would need 3,600 * 2.8 = 10,080 farads to hold it, because an amp-hour is 3,600 amp seconds. Obviously it is impractical to use capacitors to store any significant amount of power unless you do it at a high voltage. "


Size the alternator to the demand of the power amps. The caps will help with “power peaks” – don’t fall for the hype (they help reduce noise and supply “transient” demands – they are not a panacea for small a too-small alternator)…



--my opinions expressed--

 

when do you know you will need a capacitor