voltage drop
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=65263
Printed Date: May 06, 2024 at 1:13 AM
Topic: voltage drop
Posted By: Reeceddogg
Subject: voltage drop
Date Posted: October 29, 2005 at 8:34 PM
at the battery my voltage is 14.3 running at idle but measured at the amps in my trunk it only 13.9 what could be the cause for this drop
Replies:
Posted By: xetmes
Date Posted: October 29, 2005 at 9:28 PM
resistance
v = I*R, greater the current draw or resistance, greater the voltage drop
Posted By: DYohn
Date Posted: October 29, 2005 at 10:51 PM
What size power cable is running from your battery to your amps? ------------- Support the12volt.com
Posted By: bajaclawz71
Date Posted: October 30, 2005 at 12:41 AM
Could be wire size or a poor ground.
Posted By: tronmonster
Date Posted: October 30, 2005 at 8:57 AM
Poor ground will not cause a voltage drop to appear like this. It has to be wire size or a connection on the hot side.
In fact, the poorer the ground connection, the higher (up to the source voltage) the voltage reading will be at the point where power is connected to a device.
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Don't wanna hear your "boom-boom," just wanna hear my "weeee-yaaah-deedle-dee."
Posted By: geepherder
Date Posted: October 30, 2005 at 7:01 PM
Not if he's measuring voltage across the pos/neg amp terminals. A poor ground would drop some of that voltage. That's not that bad, though- 3 tenths of a volt drop.
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My ex once told me I have a perfect face for radio.
Posted By: haemphyst
Date Posted: October 30, 2005 at 7:34 PM
tronmonster wrote:
Poor ground will not cause a voltage drop to appear like this. It has to be wire size or a connection on the hot side.
If he is reading AT THE AMP TERMINALS, yes, there could be a volatage drop exhibited like this.
tronmonster wrote:
In fact, the poorer the ground connection, the higher (up to the source voltage) the voltage reading will be at the point where power is connected to a device.
Huh? Wha...? Either I don't understand exactly what it is that you are saying, or you are saying something that is completely false. Please elaborate on this statement.
And finally, I agree that .4v drop is nothing to be concerned about, ESPECIALLY if that drop is with the system running WFO. At idle, .4v could be a sign of something quite wrong in your system. ------------- 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: geepherder
Date Posted: October 30, 2005 at 7:58 PM
I thought that was 14.2. Hah. Some math whiz I am. ------------- My ex once told me I have a perfect face for radio.
Posted By: Reeceddogg
Date Posted: October 30, 2005 at 9:37 PM
i'm currently running two gauge to the distribution block where i took the measurement , split to six 8 gauges four go to my rockford 800aii, the other two to accy's. measurements: at idle with the amps on but the sound on mute.
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