capacitor grounding car
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=91241
Printed Date: June 01, 2024 at 12:02 PM
Topic: capacitor grounding car
Posted By: trentmeyer23
Subject: capacitor grounding car
Date Posted: March 03, 2007 at 11:41 PM
Hi guys, i dont want to start a debate over capacitors, but i am having a problem with my capacitor. When ever i disconnect the negative terminal on my battery, the entire car stays grounded and discharges the capacitor. I have two alpine amps hooked up to it via the distro-block on the cap. Both positive(fused) and ground wires go straight to the cap, the are split into two to go to the amps. I hope someone here can help me, Thanx in advance, Trent
Replies:
Posted By: trentmeyer23
Date Posted: March 03, 2007 at 11:53 PM
^^^i forgot to mention the ground is separate from the battery
Posted By: aznboi3644
Date Posted: March 04, 2007 at 1:35 PM
In that whole post there is not even one question
Posted By: master5
Date Posted: March 04, 2007 at 3:01 PM
I do not really see a question here either...but if i take a wild stab it seems you are wondering why the cap discharges when you disconnect the ground from the battery. This is because in a sense a cap is a battery..just a very fast charge and discharging one designed for a specific purpose..(won't get into that..can of worms..lol)... But yes..if you do this the cap will discharge as that is what they do when the voltage drops..and it certainly will drop if you disconnect the battery.......solution...... Disconnect the cap BEFORE you disconnect the battery...or...don't disconnect the battery...lol kidding...just disconnect the cap first. BTW...what does "the ground is seperate from the battery" mean? Did you ground something to another vehicles battery then yours?? I don't understand. But ..keep in mind...if the battery of the vehicle is connected properly...the vehicle is grounded. Anything else you ground to the vehicle...such as a cap..amp etc..is grounded as well..and therefore technically NOT seperate from the battery. Hope I helped a bit. -------------
Posted By: haemphyst
Date Posted: March 04, 2007 at 5:06 PM
trentmeyer23 wrote:
Hi guys, i dont want to start a debate over capacitors, but i am having a problem with my capacitor. When ever i disconnect the negative terminal on my battery, the entire car stays grounded and discharges the capacitor. I have two alpine amps hooked up to it via the distro-block on the cap. Both positive(fused) and ground wires go straight to the cap, the are split into two to go to the amps. I hope someone here can help me, Thanx in advance, Trent
It would do the same thing if you only remeoved the positive cable as well... OR if you removed BOTH cables. The accessores in the car are just drawing all of their power from the capacitor. Pretend the cap is a battery (a SECOND battery in the system). If you disconnect the front batery, while leaving the back battery connected, all the accessories would still run, right? Same thing, just a different can, that's all. ------------- 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: trentmeyer23
Date Posted: March 05, 2007 at 12:14 AM
Yeah sorry the question was supposed to be how can i stop this? I read somewhere that caps should not be discharged and recharged to quickly below about 6 volts but im not sure on the relaibility of that one...what i meant about the separate ground was that a friend told me that a way to stop this was run the negative back to the battery as a ground, but i want to be sure first. "Disconnect the cap BEFORE you disconnect the battery...or...don't disconnect the battery...lol kidding...just disconnect the cap first." Ok i tried that but it sparks pretty bad, is it supposed too? and when i reconnect which way would you say to do it? Thanx for the help so far guys
Posted By: master5
Date Posted: March 05, 2007 at 9:05 AM
Forget everything your "friend" told you. Just stick to our reccomendations..this is what most of us do everyday as a profession. As far as it "sparking" if you disconnect the cap before you disconnect the battery the cap should be charged. The cap will remain charged. If you reconnect the battery...then reconnect the cap..as long as the cap is still fully charged, it won't spark. If it is sparking that means the cap was fully or partially discharged or the battery of the car is still disconnected. -------------
Posted By: aznboi3644
Date Posted: March 05, 2007 at 3:32 PM
a cap is a "battery"...with a 1-2 second reserve capacity lol
Posted By: master5
Date Posted: March 05, 2007 at 4:50 PM
ca·pac·i·tor [kuh-pas-i-ter] noun- A "cap" is an electronic device in which 99.9% of it's users are expecting it to cure a problem which it can not, or blaming it on a problem it does not cause.....even if your "friend" told you it can.... -------------
Posted By: trentmeyer23
Date Posted: March 06, 2007 at 12:04 AM
As i said i dont wanna start a debate, my friend didnt recommend it, my brother actually gave it to me...for free...so i wasnt gunna say no i dont want it, but thanx for the recommendations guys. So there is no way to get around this without disconnecting it?
Posted By: forbidden
Date Posted: March 06, 2007 at 2:46 AM
Put a extra large breaker on the + line that is feeding back to the battery. Each time you get out, open the breaker. That should solve the problem. You can even integrate a large solenoid into the line and operate it from the AUX function of a car alarm remote control as well.
-------------
Top Secret, I can tell you but then my wife will kill me.
Posted By: master5
Date Posted: March 06, 2007 at 8:56 AM
I may be missing something here..why would the breaker need to be opened every time he gets out?? I thought this "problem" occurs only when the battery is disconnected. Unless I am not understanding what the problem actually is..a possibility.
-------------
Posted By: aznboi3644
Date Posted: March 07, 2007 at 12:48 AM
i would use a heavy duty relay...wire it up with an accessory wire so it will break the connection when the ignition is off
Posted By: master5
Date Posted: March 07, 2007 at 11:17 PM
once again I ask...why??? Why does the cap need to be disconnected every time?? I say again perhaps I am not understanding what the peoblem here actually is...but this is like saying to "cut your leg off because it has an itch".....yeah that would fix the itch..but then you have no leg..wouldn't it be better to address the itch? But besides all the analogies...I was under the impression that there wasn't a problem here...he simply didn't realize that when the battery is disconnect while the cap is still hooked up that it acted like a 2nd battery..there was no problem...just a lack of understanding what was happening. Am I correct or totally missing something here...??? Someone???? -------------
Posted By: forbidden
Date Posted: March 08, 2007 at 1:04 AM
No, I had a brain fart and did not go back and edit it in time. I actually realized what I wrote but ended up with a store full of people that I had to attend to. By then it was all too late. ------------- Top Secret, I can tell you but then my wife will kill me.
Posted By: master5
Date Posted: March 08, 2007 at 3:48 PM
Ah the old store full of people..yeah been in that boat. The last few weeks have been dead so I actually want the boatload back..need to do some promotions for the spring rush however when it gets back to normal "kaos" as opposed to the slow kaos this month. -------------
Posted By: xtremej
Date Posted: March 08, 2007 at 4:29 PM
good to hear others get dead spots in the year also:)
Posted By: trentmeyer23
Date Posted: March 09, 2007 at 12:00 AM
Ok, say i dont disconnect the cap and it runs flat, when i reconnect the battery and it recharges will it have an adverse effects on the capacitor?
Posted By: master5
Date Posted: March 09, 2007 at 1:11 PM
Yeah..from what I hear "through the grapevine" from my good buddies who are industry insiders that most of the northeast is slow right now..so yes..it is many of us dealing with this..for now we are doing home audio to hold us over..our fingers are crossed that spring will pick up as it always has. I also noticed that quite a few "mom and pops" have been closing up shop...a sad state of affairs..but selfishly I can only hope this brings more business to us..I have noticed we are getting customers from alot farther away then usual. Guess it's a sign of the times. Trentmeyer23, I personally have not seen reconnecting a battery damage a cap..however this is not to say it is impossible. Also..the spark at the battery from charging the cap fast is a safty hazard. I would reccomend to have the cap disconnected before you connect the battery terminal and make sure the cap is charged as well to prevent arcing. If disconnecting your battery is something you do very often for whatever reason..one of the above suggestions using a breaker might be good for that..but if you don't do this very often..it is not worth the time and money IMO. -------------
|