capacitor

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=100083
Printed Date: May 12, 2025 at 8:00 AM

Topic: capacitor

Posted By: acer4
Subject: capacitor
Date Posted: December 16, 2007 at 9:35 AM

installed a compacitor wondering if the power supposed to stay on when car is not running or keys out of ignition

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Newfie

Replies:

Posted By: KPierson
Date Posted: December 16, 2007 at 9:41 AM

How did you hook it up? Directly to the battery?

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Kevin Pierson

Posted By: acer4
Date Posted: December 16, 2007 at 9:46 AM

From the battery with fuseable link to the compacitor then to the amp

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Newfie

Posted By: aznboi3644
Date Posted: December 16, 2007 at 12:06 PM

what kind of systen do you have??

amps??

speaker??

wire gauge??

Posted By: KPierson
Date Posted: December 16, 2007 at 1:51 PM

Well, if you hooked it directly to the battery, what would make your capacitor 'know' when to shut off and turn on?

Some of them have remote turn on leads for things like voltage displays, but even if the display is on all the time it probably won't cause any issues.

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Kevin Pierson

Posted By: acer4
Date Posted: December 16, 2007 at 6:27 PM

Hey i don't think the compacitor was fully charged when i checked the compacitor the power was off

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Newfie

Posted By: tedmond
Date Posted: December 16, 2007 at 7:32 PM

some capacitors have a turn on lead which is only used to trigger the LCD display readout. but the cap is still functional. Some that dont have it rely on voltage sensing. When the voltage is 12.6volts or below, the cap will automatically turn off. When the car has started and the voltage is spiked to 14.4 on average, the cap is now turned back on. Remember, the display is just there, it doesnt control the cap. the good thing about the caps without turn on leads, when the battery is low in power, and the amp draws too much, the cap will turn on and supply the power needed for the amp.

Posted By: greenbroncoguy
Date Posted: December 16, 2007 at 9:42 PM

tedmond wrote:

some capacitors have a turn on lead which is only used to trigger the LCD display readout. but the cap is still functional. Some that dont have it rely on voltage sensing. When the voltage is 12.6volts or below, the cap will automatically turn off. When the car has started and the voltage is spiked to 14.4 on average, the cap is now turned back on. Remember, the display is just there, it doesnt control the cap. the good thing about the caps without turn on leads, when the battery is low in power, and the amp draws too much, the cap will turn on and supply the power needed for the amp.

Forgive me for my ignorance, but how is a capacitor going to "supply" an amp with anything if the battery (which is ultimately where that awsome cap gets it power from when the car's engine is not running) is low? The capacitor can't give power if it can't get any...

Posted By: haemphyst
Date Posted: December 17, 2007 at 8:11 AM

tedmond wrote:

some capacitors have a turn on lead which is only used to trigger the LCD display readout. but the cap is still functional. Some that dont have it rely on voltage sensing. When the voltage is 12.6volts or below, the cap will automatically turn off. When the car has started and the voltage is spiked to 14.4 on average, the cap is now turned back on. Remember, the display is just there, it doesnt control the cap. the good thing about the caps without turn on leads, when the battery is low in power, and the amp draws too much, the cap will turn on and supply the power needed for the amp.

In the year since you joined, tedmond, I am CERTAIN we have had at least ONE knock-down, drag-out argument/discussion regarding the "functionality" of capacitors. Where have you been, or did you think you already knew everything there was to know about caps, so you didn't read it? Whether there is a remote lead or not, all cRapacitors will function IDENTICALLY. The remote is to simply turn the display on, and nothing more.

Generally, though, your post is completely FALSE information. The cap's voltage will be at whatever the battery's voltage is. So, if the battery is low on power, so is the cap. Go read some of the threads and stickies regarding capacitors before spreading stuff like that.

(BTW, LCD stands for "Liquid Crystal Display", so when you write LCD display, you are writing "liquid crystal display display"... Same thing applies to ATM (Automated Teller Machine) and ATM Machine, PIN (Personal Identification Number) and PIN Number. SSN, VIN... There are more, but you get the idea, whether you have used them here or not... It's redundant, so stop doing it, EVERYBODY!!! posted_image

)

TO THE OP:
acer4, does the cap have a display? If not, the cap will "work" without a remote lead. If it does, and you installed the remote lead, and the display stays on even with the car off, you might have a bad display board. You can try to exchange the cap, or remove the display completely, it'll work just the same - i.e. it won't.

Did you address your charging system first? If not, then the cap will fix nothing, and you'll be back here, and soon, asking how to do that.

If the cap is attached to the battery, it is "fully charged", whether the display is on or off.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Posted By: greenbroncoguy
Date Posted: December 17, 2007 at 12:26 PM

^^^ Exactly. Alot of people have this thought that a capacitor will somehow magically add electrical power to their audio system, when it is more or less just another small battery(that your stock alternator must now try to keep charged along with running the rest of your car).

"the good thing about the caps without turn on leads, when the battery is low in power, and the amp draws too much, the cap will turn on and supply the power needed for the amp." - What the hell does this even mean? It sounds like you are trying to sell someone a capacitor to me. How does a cap even "turn on"? The display may turn on with the ignition, but if the capacitor in question is charged(again, like a battery), it wil be able to provide power to whatever is hooked to it. HOWEVER, if the battery power is low(where the cap is getting all it's power), the electrical power that is able to be supplied by the cap will be just as low...

Posted By: dragon51
Date Posted: December 17, 2007 at 5:31 PM

Acer4 just do your self a favor and do a search on caps. You will learn 2 things that caps do the most.

1. Deprive your wallet of money

2. Makes a purdy banaid! posted_image

Make your money go futher and put it towards a bigger alt, read Big 3 its a sticky posted_image