discharging a cap

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=113593
Printed Date: July 04, 2025 at 5:52 PM

Topic: discharging a cap

Posted By: djrankin004
Subject: discharging a cap
Date Posted: May 04, 2009 at 4:26 PM

i have two 12' type x's and a kicker 850.2 that i am currently trying to sell. Hooked up to this is a tsunami 1.2 farad capacitor. My question is is there any reason why i can't just take the power and ground wire off the capacitor and sell it as is? Does the cap need to be discharged? I've heard that to discharge the cap i can take the power fuse in line to the battery out and turn on the stereo until the amp drains the capacitor of its power, would this be a effective and safe way to do it if i need to at all?

Replies:

Posted By: Velocity Motors
Date Posted: May 04, 2009 at 4:39 PM

The reason that the cap needs to be discharged is because the cap stores energy and if you remove the (+) and the (-) terminals, that doesn't release the last amount of charge that's still in the cap. By properly discharging the cap with a resistor, this will empty out the cap and will not cause any problems.

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA

Posted By: t&t tech
Date Posted: May 04, 2009 at 4:39 PM

The safe way to discharge a stiffening capacitor is after the battery is disconnected, connect your charging resistor (or a test light or a 10watt resistor) across the positive and negative terminals. Leave it there until you are ready to re-connect the battery, and then remove it.

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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5

Posted By: t&t tech
Date Posted: May 04, 2009 at 4:40 PM

sorry velocity posted while you were posted_image

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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5

Posted By: djrankin004
Date Posted: May 04, 2009 at 5:34 PM

i think they come with a resistor...dont have it anymore tho. Where can i get one? or the test light you are talking about? and then what do i do with it? just connect between the positive and negative terminals?