educate me.. can long grounds cause voltage loss?

[vandiar2 10+ year member]

id say the grounds going to both of my amps are roughly 3 feet. will this cause voltage loss? I am certain I will need another battery up front. Just want to start with the basics first. I'm pretty sure I can shorten up the grounds, but is it necessary. My amps are seeing roughly 12.2 volts (not good :/ lights dim). thanks!

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[MkKin420 10+ year member]

If its big enough wire, say 1/0 gauge, than it shouldn't be a problem. Im not sure how much of a voltage drop you may see if any but the smaller the wire the less current it can carry, and higher resistance when carrying a load. Basically, Bigger wire=less resistance, If you are really worried about it just replace them with larger gauge cable. One from battery - to frame/chassis and one to engine body.

 

[traksta15 10+ year member]

I always wondered this too

 

[vandiar2 10+ year member]

If its big enough wire, say 1/0 gauge, than it shouldn't be a problem. Im not sure how much of a voltage drop you may see if any but the smaller the wire the less current it can carry, and higher resistance when carrying a load. Basically, Bigger wire=less resistance, If you are really worried about it just replace them with larger gauge cable. One from battery - to frame/chassis and one to engine body.

I am already using 1/0 wire for the sub amp, and already have the big 3 done. just wondering if shortening up my grounds would reduce the voltage loss I am having.

 

[I Like Waffle]

if you have slack in them i would def shorten them. I try to keep mine under 2ft.

 

[MkKin420 10+ year member]

For sure shorten them if you can. What kind and capacity battery are you running? Are your amps seeing 12.2 with the car on? Whats is the voltage at your battery with the car off? On?

 

[vandiar2 10+ year member]

if you have slack in them i would def shorten them. I try to keep mine under 2ft.

Yeah I need to.. just isn't enough time in the day. I threw everything in there saturday.. started saturday mourning. by time I "finished" it was like 7:30 at night and I couldn't see so I was in sort of a rush. I need to work on it a lot more.

 

[vandiar2 10+ year member]

For sure shorten them if you can. What kind and capacity battery are you running? Are your amps seeing 12.2 with the car on? Whats is the voltage at your battery with the car off? On?

yup 12.2 at the 4 channel with the car on. both batteries test fine with the car off (12.7-.8) and without the cd player on, the 4 channel test about 14.2. . I have a batcap 2000 in the back, and a duralast (pretty sure it is a stock battery) in the front. reserve on it is 90, and only 500 cca. I am pretty sure I need to throw something else up front.

 

[MkKin420 10+ year member]

So basically with your amps on and not playing any music (idle) your voltage at the amps drops down under 13v. Perhaps your problem lies in the mixing of the two kinds of batteries, that duralast might be wearing down your battcap, How long have you had the second battery? How much power are your amps rated for? What are the fuse ratings? What about your alternator? Do you keep your batteries as fully charged as possible?

 

[vandiar2 10+ year member]

So basically with your amps on and not playing any music (idle) your voltage at the amps drops down under 13v. Perhaps your problem lies in the mixing of the two kinds of batteries, that duralast might be wearing down your battcap, How long have you had the second battery? How much power are your amps rated for? What are the fuse ratings? What about your alternator? Do you keep your batteries as fully charged as possible?

no sorry, I think you misunderstood me. while everything is idle, my amps see about 14.2 volts. its when I crank it up, it hits around 12.2. I just put that second battery in about a week ago. It rest at about 12. 8 though. 1/0 gauge wire, with 250 amp knu fuse holders. the 4 channel i only about 100 W rms, and the sundown 1500.. 1500 rms (though I don't think I quite have it set that high .. yet) haven't tuned the sundown with a volt meter yet was planning on doing it all this weekend. alternator is good but its only 90 amps. define a fully charged battery? They all rest good, or so my volt meter says

 

[MkKin420 10+ year member]

I mean do you take time to drive around without the music going so that the batteries have a chance to redeem themselves? Or by chance do you charge them when the car is off with an external charger or maintainer? When music is playing it is dynamic and draws all sorts of current for different frequencies your batteries might not be able to keep up with the entire demand of your system, or your alt might have something to do with it. Just my $.02.

 

[vandiar2 10+ year member]

I mean do you take time to drive around without the music going so that the batteries have a chance to redeem themselves? Or by chance do you charge them when the car is off with an external charger or maintainer? When music is playing it is dynamic and draws all sorts of current for different frequencies your batteries might not be able to keep up with the entire demand of your system, or your alt might have something to do with it. Just my $.02.

Yeah I do drive around with my music turned down sometimes. Thanks for all of your help. I think I am going to go back, redo all of my grounds.. and look for another battery up front. since I have a batcap 2000 in the back, should I get another batcap to put up front? or can I put something like a deka, or PM, or kinetik etc up front.

 

[MkKin420 10+ year member]

If you can fit it you could prolly just get the biggest deka, kinetic, ect. for upfront, it might help, but before you go and spend money do anything you can that doesn't cost you much, or anything, and see if that works. Check your alternator as well, and driving around a little bit with the music turned down still draws current from the batteries. What I do is drive around for like 15 minutes the first time I start the car, then bump and whatnot, then at the end of the day I drive around for another good 15 minutes with the stereo off and park for the night. Another thing is if the lights are on, they too require current, and quite a bit of it so your available power to the amps and lights goes down as well (dimming).

 

[Rashaddd 5,000+ posts]

extra ground wire is just like extra positive wire...generally you want to keep total wire lengths to a minimum, but would you be freaking out if your car was 2ft longer?

 

[DammitJames 10+ year member]

id say the grounds going to both of my amps are roughly 3 feet. will this cause voltage loss? I am certain I will need another battery up front. Just want to start with the basics first. I'm pretty sure I can shorten up the grounds, but is it necessary. My amps are seeing roughly 12.2 volts (not good :/ lights dim). thanks!

this is the easist way to tell right here its called a voltage drop take a DMM and put it on dc volts turn the amps on and have em drawing some kinda power(they have to be using power for it to work right) then put on meter lead on one end of ur wire then the other one on the other end of the wire(on the same wire not a + and - still hooked up to the amps or whatever it is) with the amps on and drawing power(playing) the DMM should read 0v anything more means u are losing voltage in your wires this is a common practice in the automotive industry for checking starter and alt wires it will work on the positive and negative wires just make sure ur leads are on the same wire