can you ground second battery on frame?

[tommyk90 5,000+ posts]

i guess since you cant ground the back batt to the frame and get a good ground you also cant ground the front batt to the frame and get a good ground. so where exactly do you people that say you gotta run the back ground off the front batts neg suggest the ground should go? maybe drive a copper pipe into the ground and connect to that? i mean cars have been around how long? and they've apparently been doing it wrong the whole time. tell me exactly how the fuck the frame in the back is different than the frame in the front??

A cars electrical system draw is minimal compared to car audio systems.

Plus, as already stated, all the electronics (including the fuseblock) are all in the FRONT of the vehicle, close to the battery and alternator.

The longer the conductor, the less current it can handle. So while the frame up front could handle a decent amount of current because of the close promixity to the alternator and battery, trying to draw the same amount of current through the entire length of the frame WILL cause issues with larger setups.

Please don't make an *** out of yourself for the 2nd time today.

And to the OP, grounding to the chassis will be fine for your application, HOWEVER I do think you should get a larger battery for the back and replace the one up front if you haven't already.

It's best to have two batteries that are matching in type and size. Mixing a normal lead acid battery with a sealed AGM like a kinetik is a no no in most cases.

Also, don't forget to fuse the power wire going to the rear battery ON BOTH ENDS. One fuse close to the front battery, then another fuse before the rear battery.

 

[jco1385 5,000+ posts]

if any of you could comprehend above a 1st grade level you would understand what i'm asking. how is running a wire no matter how big the wire is from the front battery any better if the front battery is grounded to the frame? simple really, the frame is the frame front or back. therefore it is a waste of time,energy and money to run wire from front to back for the ground.

ever heard of resistance?

 

[lilmaniac2 5,000+ posts]

if any of you could comprehend above a 1st grade level you would understand what i'm asking. how is running a wire no matter how big the wire is from the front battery any better if the front battery is grounded to the frame? simple really, the frame is the frame front or back. therefore it is a waste of time,energy and money to run wire from front to back for the ground.

riiiiiight so were all wrong on both threads and your the only one right.

Read my posts, I realize that they are long and have some decently long words in them but maybe you'll learn something.

 

[01 S 10 10+ year member]

ever heard of resistance?

LOL

he's a tard, he can't think that hard.

 

[natisfynest 10+ year member]

i have to agree with scarolinablazin

grounding to the frame/chassis/body in the front is the same as grounding to the back

i mean when you ground your amp you dont run a ground wire all the way back up to the front to the neg side of the battery do you???

 

[tommyk90 5,000+ posts]

i have to agree with scarolinablazin
grounding to the frame/chassis/body in the front is the same as grounding to the back

i mean when you ground your amp you dont run a ground wire all the way back up to the front to the neg side of the battery do you???

No, you're wrong. Thanks for playing.

Grounding to the front is completely different. The current has a MUCH shorter path to follow and thus more current can be pulled through the steel.

The same can be said for a piece of copper. A 15 foot piece of copper CANNOT handle as much current as a 3 foot piece. These are laws of electricity/conductivity.

And yes, as a matter of fact, I do have my amp ground ran to the batteries under my hood.

 

[vandiar2 10+ year member]

A cars electrical system draw is minimal compared to car audio systems.
Plus, as already stated, all the electronics (including the fuseblock) are all in the FRONT of the vehicle, close to the battery and alternator.

The longer the conductor, the less current it can handle. So while the frame up front could handle a decent amount of current because of the close promixity to the alternator and battery, trying to draw the same amount of current through the entire length of the frame WILL cause issues with larger setups.

Please don't make an *** out of yourself for the 2nd time today.

And to the OP, grounding to the chassis will be fine for your application, HOWEVER I do think you should get a larger battery for the back and replace the one up front if you haven't already.

It's best to have two batteries that are matching in type and size. Mixing a normal lead acid battery with a sealed AGM like a kinetik is a no no in most cases.

Also, don't forget to fuse the power wire going to the rear battery ON BOTH ENDS. One fuse close to the front battery, then another fuse before the rear battery.

elaborate on the matching battery please. i was thinking of putting a yellow top up front but guess what, according to their website there isn't one that fit. in the front of my car.. what would you recommend? if i got a really good battery up front (if i can find one that will fit) think that would suffice my rms power using a distro block instead of a second battery with the big 3 done? my car is a 1996 dodge neon.

 

[scarolinablazin 10+ year member]

i can't believe that some of the people i used to think had a little bit of common sense are really this stupid. i don't care how many of you decide to rub each others nuts {egos} you're all wrong. if the battery is grounded to the FRAME in the front to begin with running a wire no matter how big will actually have more resistance than grounding the back battery to the frame. you would have the original from the frame {same in the front as it would be in the back} plus that of that long *** piece of wire going from the front to the back. you all FAIL at common sense and life.

 

[audioholic 5,000+ posts]

Quoted from Esoteric Audio (Street Wires)

Article Date: 1997

The current Esoteric Audio web site no longer has “White Papers” like this one.

Best Place to Ground Your System

The floor pan of a car will generally carry more current than a 1/0 cable of any sizable length. You always want to minimize resistance by keeping all runs as short as possible. This includes the chassis. You always want to connect all ground cables to the same chassis part. This confuses some people, so let me explain, If you have a truck, always run the ground cables to one of the frame rails, or the floor pan of the cab. Do not run the ground under the hood to the left frame rail and the ground cable in the back to the right frame rail.

Sometimes you will want to use the body as the ground. There is nothing wrong with this, but be sure to connect to the same piece of metal in the front as you do in the back, such as the floor pan.

There are not very many cars with a full frame anymore, so we can pretty much exclude that here. I firmly believe that the most important points to remember in this case are to connect to the floorpan of the car both under the hood and in the trunk, and to remove all paint and any contaminates such as body filler or grease from the point that the cable is connected to the body (or frame). In fact the removal of the paint from the metal surface will probably have as big of an effect on your voltage drop as anything. This is an absolute must and should be done in every case without question.

I can not think of a single car that I have seen that did not have a single large piece of sheet metal for the floor pan. Knowing this you always want to attach your ground in the front and rear of your vehicle to this piece of metal.

The reason for this is simple: fewer connections and therefore less resistance. I will make a way over-simple illustration here. Joe grounds his front battery to the strut tower on his Grand Am. In the trunk, he grounds his system to the fender well with a bolt. In both places he removes all paint and filler to be sure he makes good contact. His ground is not as good as it could be because he has current flow through an unknown (and possibly variable) number of connections. Some are spot welds, some may be bolted (who knows?) but the fact is that there are quite a few unnecessary "connections" here. By making sure that you connect your ground points to the same body panel, you will assure yourself of the best possible ground.

We ran a series of tests to put some actual numbers to some of the methods used by installers . This data may surprise you.

Here is some of the data, and the outline of the procedure.

We have a lab grade machine custom built by a company in Atlanta that is capable of measuring voltage, current and voltage drop through a circuit in real time. It will repeat these measurements in the 500 amp range with remarkable precision. The current level is infinitely adjustable and all of the units (voltage, current and voltage drop) are given in real time using real numbers based on a reference taken at the outputs. The cables that we used for our measurements were measured before and after the test to assure that we could "back them out" of our measurements and determine an actual value. We used a 1985 Camaro for the test vehicle. We chose a spot in the front of the car that an installer may choose to ground the alternator and battery under the hood, and also one in the back of the car where someone may ground an amplifier. We then measured the voltage drop @ 300 amps with the cables connected using various methods.

The first two tests were done with both ends of the reference cable fastened in the same fashion.

Test 1-- Sheet metal screw to non sanded metal- .25 volt drop

Test 2-- Sheet metal screw to sanded metal- .13 volt drop

All tests below this point were done with the front connection fastened with a 5/16 bolt through sanded metal.

Test 3-- 5/16 bolt to non sanded metal- .23volt drop

Test 4-- 5/16 bolt to sanded metal- .09 volt drop

Test 5-- 6mm existing stud painted and not sanded .24 volt drop

Test 6-- 5/16 bolt to sanded metal, on a spot welded bracket-- could only attain 244 amps, voltage drop was approximately 5 volts.

Test 7-- 3/8 bolt to non sanded seat belt mounting nut--.15 volt drop

These tests were done using the floorpan as the ground path (except #5 and 6). Other tests using panels attached to the floorpan of the car revealed various voltage drops. We measured drops up to 1.25 volts during the testing. I am quite sure that this will be different for every vehicle on the road today, but has shown that the best place to ground your system is to the floorpan, and shown that doing the extra work to sand the paint from the metal pays a rather large dividend.

©1997 Esoteric Audio USA

 

[tommyk90 5,000+ posts]

elaborate on the matching battery please. i was thinking of putting a yellow top up front but guess what, according to their website it won't fit. what would you recommend? if i got a really good battery up front (if i can find one that will fit) think that would suffice my rms power using a distro block instead of a second battery with the big 3 done? my car is a 1996 dodge neon.

You could go with 2 kinetiks and be fine. My recommendation to you is to just get the largest batteries you can fit/afford.

A yellowtop and a kinetik would be fine since they are both AGM style batteries.

It's better to have MORE battery than you need than not enough. Plus this leaves room for upgrading.

 

[tommyk90 5,000+ posts]

Quoted from Esoteric Audio (Street Wires)Article Date: 1997

The current Esoteric Audio web site no longer has “White Papers” like this one.

Best Place to Ground Your System

The floor pan of a car will generally carry more current than a 1/0 cable of any sizable length. You always want to minimize resistance by keeping all runs as short as possible. This includes the chassis. You always want to connect all ground cables to the same chassis part. This confuses some people, so let me explain, If you have a truck, always run the ground cables to one of the frame rails, or the floor pan of the cab. Do not run the ground under the hood to the left frame rail and the ground cable in the back to the right frame rail.

Sometimes you will want to use the body as the ground. There is nothing wrong with this, but be sure to connect to the same piece of metal in the front as you do in the back, such as the floor pan.

There are not very many cars with a full frame anymore, so we can pretty much exclude that here. I firmly believe that the most important points to remember in this case are to connect to the floorpan of the car both under the hood and in the trunk, and to remove all paint and any contaminates such as body filler or grease from the point that the cable is connected to the body (or frame). In fact the removal of the paint from the metal surface will probably have as big of an effect on your voltage drop as anything. This is an absolute must and should be done in every case without question.

I can not think of a single car that I have seen that did not have a single large piece of sheet metal for the floor pan. Knowing this you always want to attach your ground in the front and rear of your vehicle to this piece of metal.

The reason for this is simple: fewer connections and therefore less resistance. I will make a way over-simple illustration here. Joe grounds his front battery to the strut tower on his Grand Am. In the trunk, he grounds his system to the fender well with a bolt. In both places he removes all paint and filler to be sure he makes good contact. His ground is not as good as it could be because he has current flow through an unknown (and possibly variable) number of connections. Some are spot welds, some may be bolted (who knows?) but the fact is that there are quite a few unnecessary "connections" here. By making sure that you connect your ground points to the same body panel, you will assure yourself of the best possible ground.

We ran a series of tests to put some actual numbers to some of the methods used by installers . This data may surprise you.

Here is some of the data, and the outline of the procedure.

We have a lab grade machine custom built by a company in Atlanta that is capable of measuring voltage, current and voltage drop through a circuit in real time. It will repeat these measurements in the 500 amp range with remarkable precision. The current level is infinitely adjustable and all of the units (voltage, current and voltage drop) are given in real time using real numbers based on a reference taken at the outputs. The cables that we used for our measurements were measured before and after the test to assure that we could "back them out" of our measurements and determine an actual value. We used a 1985 Camaro for the test vehicle. We chose a spot in the front of the car that an installer may choose to ground the alternator and battery under the hood, and also one in the back of the car where someone may ground an amplifier. We then measured the voltage drop @ 300 amps with the cables connected using various methods.

The first two tests were done with both ends of the reference cable fastened in the same fashion.

Test 1-- Sheet metal screw to non sanded metal- .25 volt drop

Test 2-- Sheet metal screw to sanded metal- .13 volt drop

All tests below this point were done with the front connection fastened with a 5/16 bolt through sanded metal.

Test 3-- 5/16 bolt to non sanded metal- .23volt drop

Test 4-- 5/16 bolt to sanded metal- .09 volt drop

Test 5-- 6mm existing stud painted and not sanded .24 volt drop

Test 6-- 5/16 bolt to sanded metal, on a spot welded bracket-- could only attain 244 amps, voltage drop was approximately 5 volts.

Test 7-- 3/8 bolt to non sanded seat belt mounting nut--.15 volt drop

These tests were done using the floorpan as the ground path (except #5 and 6). Other tests using panels attached to the floorpan of the car revealed various voltage drops. We measured drops up to 1.25 volts during the testing. I am quite sure that this will be different for every vehicle on the road today, but has shown that the best place to ground your system is to the floorpan, and shown that doing the extra work to sand the paint from the metal pays a rather large dividend.

©1997 Esoteric Audio USA

Tell this to db drag people and they will laugh at you. Though they are usually pulling much more current than 300 amps.

My teammate was trying to pull 1000+ amps through his frame and was getting MAD voltage drops. Tossed in two runs of 1/0 and the problem was solved.

Also, its funny that they mentioned 1/0 not being able to handle as much current, but they don't actually test it? Sounds fishy to me.

 

[vandiar2 10+ year member]

You could go with 2 kinetiks and be fine. My recommendation to you is to just get the largest batteries you can fit/afford.
A yellowtop and a kinetik would be fine since they are both AGM style batteries.

It's better to have MORE battery than you need than not enough. Plus this leaves room for upgrading.

again, yellowtop is not going to fit under my hood and from my understanding deep cycle batteries are not to be used for cranking a vehicle. thats what i am confused about.

 

[scarolinablazin 10+ year member]

Tell this to db drag people and they will laugh at you. Though they are usually pulling much more current than 300 amps.
My teammate was trying to pull 1000+ amps through his frame and was getting MAD voltage drops. Tossed in two runs of 1/0 and the problem was solved.

Also, its funny that they mentioned 1/0 not being able to handle as much current, but they don't actually test it? Sounds fishy to me.

seems to me these people whose buisness depends on this would know MORE than you and agree with what i'm saying. hope you have small feet cause they're now in your mouth.

 

[jco1385 5,000+ posts]

oh lawd

 

[Loud3 10+ year member]

seems to me these people whose buisness depends on this would know MORE than you and agree with what i'm saying. hope you have small feet cause they're now in your mouth.

The truth of the matter is that people will write whatever they want to make the sale. Whether it's true or not.

And the real truth of the matter is, Tommy is correct. It has been documented/proven many times.

You should actually open up your mind and attempt to learn something new, instead of blocking out any potentially useful info.