2g Battery Relocation

[DSM4LIFE-AWD]

After reading and searching all day long I came up with this draw.

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I still dont know if its the way to go ... Some threads say that you need to put an other 80 amp fuse near the starter ? Some say that the circuit breaker need to be after the switch ?

Well I used the diagram that came with the moroso kill-switch to do this picture and I want to know if I miss something before I put fire in my dsm ...

Thanks

 

[Ibbanez]

Actually the way I did mine was this:

1) took all the wires off the positive and ran them to a distribution block
2) grounded the negative to the car chassis
3) ran wire the the rear of the car to a blade style fuse block (150 amp)
4) from fuse block to battery
5) grounded negative battery to chassis

the terminals I bought have extra room for other wires.....ie fuel pump rewire.

 

[Jafro]

So you didn't run a separate line from the alternator to the battery? How's that worked out for ya?

 

[talonalex92]

Actually the way I did mine was this:

1) took all the wires off the positive and ran them to a distribution block
2) grounded the negative to the car chassis
3) ran wire the the rear of the car to a blade style fuse block (150 amp)
4) from fuse block to battery
5) grounded negative battery to chassis

the terminals I bought have extra room for other wires.....ie fuel pump rewire.

Ditto. I havent had any issues at all. Been like that about 6 months now. I did however, add a few more grounds in the back and in the engine bay. They definatly seem to help with things after the relocate.
Heres where I put the batt.

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Heres underhood.

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[Jafro]

Welp,

I already committed to running a separate alternator circuit. I did C. The alternator line attaches to the battery pole of the main breaker. I figure it really makes no difference if the 2 white wires from the alternator circuit pull 12v from the main rather than the alternator feeding it directly inside the fuse box. That circuit is bridged by the 100A fuse, so... Either way, the alternator makes it back to the battery +, and I can kill the alternator circuit with the breaker in the trunk (for service).

I'm fabricating a breaker panel tonight. I've been creative with welding nuts on the back of sheetmetal so that I can easily bolt everything down. I did that on the plate for the battery box and it worked out great for the tie-down rods. I wont have to fumble around with fasteners on the bottom of it whenever I have to remove the battery. Just un-screw the studs if I have to.

Here's where I put it. The plate is 14ga steel welded into the floorpan. The battery box fits below the spare tire lid. I'll figure something out with the washer bottle later... but I like how well hidden this will be. The breakers will fit between the box and the spare tire well leaving me room to access the reset switches, while keeping all the insulated terminals out of harm's way.

 

[tsiboostin]

Actually the way I did mine was this:

1) took all the wires off the positive and ran them to a distribution block
2) grounded the negative to the car chassis
3) ran wire the the rear of the car to a blade style fuse block (150 amp)
4) from fuse block to battery
5) grounded negative battery to chassis

the terminals I bought have extra room for other wires.....ie fuel pump rewire.

This is how I also plan to do mine. On test and tune days they never tech much. If I do need to add a cut off it won't be hard with the fuel pump rewire so close.

 

[knochgoon24]

This is how I also plan to do mine. On test and tune days they never tech much. If I do need to add a cut off it won't be hard with the fuel pump rewire so close.

But that won't cut power from the alternator like a proper cut off switch should.

 

[Project2G]

Heres where I put the batt.

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This would not pass tech since it's not in a battery box am I correct?

 

[Jafro]

But that won't cut power from the alternator like a proper cut off switch should.

I doubt he has a switch, but you're correct, It will not cut power. If the engine's running and the main blows/trips, it will keep running. The pic of the fuse box on the previous page shows why. The alternator feeds on the engine component side of the fuse, not the battery side. But that's how it's wired to function stock, anyway.

This would not pass tech since it's not in a battery box am I correct?

Correct.

My setup wont pass tech either because there's no cut-off switch.

 

[talonalex92]

I have never been teched. Ever. Our dragways up here are pretty lame. You could probably run a car with no wheels and they wouldnt notice.

 

[turbosax2]

Here's mine.

http://www.dsmtuners.com/forums/152022910-post471.html

 

[snowborder714]

Just an update - we started my brother's car with the battery relocated per the diagram I posted above with no issues. The kill switch works perfectly as well.

 

[Clutch GSX]

Jafro,

Could you draw up a diagram for how you did it? It would be real helpful for us visual guys.

Thanks.

 

[Jafro]

Jafro,

Could you draw up a diagram for how you did it? It would be real helpful for us visual guys.

Thanks.

Man....

I am so sorry I haven't been back in here. I never got notification of an update on this thread. I'm guilty of the ONE thing I detest, and that's when someone has a solution, and doesn't follow up on what worked for others.

I posted a diagram of the wiring on the previous page, but I didn't wire the alternator exactly as it's drawn in that image. Most of that is because the convenient and safest wiring schematic for it was to use the factory alternator lines all the way to where it used to bolt into the fuse box, and splice it into a fuse for the 4ga dedicated alternator wire that goes back to the battery side of the main circuit breaker. You could run the wire all the way to the charge pole, but that wire still needs to be fused in the engine bay as well as within inches of the battery poles. A short could occur so far from the breaker that it wouldn't do anything to stop a fire, and the alternator is a power source as well.

I don't just have a diagram. In addition to that, there's a youtube video. I'm answering this here because I also failed to include a link to this thread there. I couldn't have done any of this without your help.

YouTube - GSX Battery Relocation

Edit: Here's the revised diagram:

 

[Guzman08]

cool video.. wish i could relocate my battery that fast..

 

[waggs187]

For someone just wanting to relocate to the trunk without the kill switch....would you just run one wire to the engine bay and tie everything in to a distribution box? Everything use to just go to the battery. The only difference is that you have a ground in the trunk and in the engine bay correct? I got the kit for STM and I'm not too sure how to set this thing up. I've read these post about 15 times and I still don't understand. There should be the ground from the starter to the engine bay and then the positive wire from the starter to a distribution box and the four white wires from the Fuse box/ Relay box to the distribution box right? why run two seperate wires to the battery for the alt and starter?

 

[Jafro]

I still don't understand why people feel the need to re-quote text that's immediately above? Maybe it's just an ego thing to make big unnecessary posts? Maybe it's a social disorder? Too much lead paint?

 

[knochgoon24]

You won't charge your battery if you do it that way. If you tie the alternator into the fuse box up front, you're charging your fuse box, not your battery. If you have a short before that point, the breaker won't kill the engine because the alternator is still powering everything through the main fuse in the fuse box (including the short upstream). It needs to stop the charging, thus preventing a fire.

You have to consider the DC flow of what the + wire does. The alternator charges the battery and flows from the battery to the fuse box, to the components in the car. The alternator connects to the battery with the two white wires illustrated in the pictures I posted. If you put the battery on the other end of 12 feet of wire, it has to send power backwards against the current to charge the battery while the battery is sending power back to the fuse box. That won't really work. The alternator has to have a dedicated line. You have to have fuses or breakers within a foot of the battery terminals. It takes 2 wires to do it correctly.

If you click through to the YouTube video I posted earlier, there's a more detailed description of why it needs to be done this way in the video info.

You don't understand how DC power works. There's no set direction. It's all about potential (voltage) differences.

Think of the electrical system this way:
-The alternator is a water pump
-The battery is a bucket (actually, an expansion tank like on your hot water heater. It can hold pressure too.)
-All the electrical things in the car are holes in the line between the water pump and the bucket.

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The water pump's job is to supply enough water at a high enough pressure to keep the bucket full and proper flow out all the holes. If you open more holes, the pressure in the system drops, so the water pump has pump more water to maintain the same pressure. The bucket holds extra water for use when the pump can't supply enough. It's a buffer. Water is used from the bucket while water is in high demand and the pump can't supply enough. When demand drops and pump can flow enough to water to fill the holes, it will also refill the bucket. Water can flow either way though the hose or even both ways at the same time, some from the pump towards the leaks, and some from the bucket towards the leaks. It won't flow both directions in the same spot though. If you have more flow than necessary (so pressure starts increasing), the regulator on the pump will sense the rise in pressure and dial back the output of the pump.

This is just like how the electrical system in our car works. The water's pressure represents the voltage and the water's flow is the current. The more things using electricity, the more "leaks" you have, and the more current needs to be supplied. The battery acts like a buffer. It reacts to the changes in demand instantly. It's output can be nearly constant. However, since the alternator is run off the engine by a belt, it's maximum current output varies with rpm. All voltage represents is a pressure, just like the oil pressure in your car.

Also, if you have your wire coming from the alternator to the fuse box (like stock), there's a 100A fuse there, so it's not like there's no protection. If there's a short between the fuse box and the battery, the circuit breaker from the battery to the short will trip, stopping flow from the battery, but the alternator fuse may also blow, stopping power from the alternator.

For comparison, here's my setup.

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It's been in the car now for 3 months now with 0 problems.

In my opinion, your way wasted about 15-20 feet of wire, a fuse, and a splitter.

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And actually, in both my setup and the way I redrew yours, both could have the circuit breakers on the engine bay side of things removed. It's never going to blow. Either the alternator fuse in the fuse box would blow, the battery circuit breaker, or both. I'm just using it in my car as a distribution block.

 

[waggs187]

Thanks everyone for your input.
1.) I didn't understand why STM would provide just some of the stuff in their package for the relocation.
2.) I kept trying to compare what I thought was right with what everyone else was doing for their cut off switch

1 +2 doesn't always equal 3. In this case it equalled confusion! So....I'll do it your way knochgoon24. Thanks for the detailed writeup.

 

[Jafro]

yawn

 

[waggs187]

My first inclination is not to be kind to you for being a judgmental jackass. Don't ever tell me what I don't know. Perhaps you have overlooked the fact that I may have done it differently than you for safety reasons, or because I have done it wrong before thinking your design would work on a 1g. I've also done it according to IHRA specs (which you clearly have not) and if I want to pass tech in an event that requires it, all I need is a kill switch. Not a kill switch, a breaker, a fuse and another wire run to the battery.

Your design is fire-prone. I'll explain it in terms of water as well since you must be a plumber.

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Just imagine with electricity where water=fire.

On your setup, you can kill the main breaker (at the battery) and the car will keep running. If you wreck your car and front-end components short out, the engine will keep running. If you're unconscious, you can die in a fire. This does not pass tech for battery relocation in any sanctioned event. If you get away with it, your techs are lazy and I would not ride in your car.

If any portion of the circuit on the main fails with my setup, it kills the engine. If you kill the main breaker, it kills the engine and the charging circuit because the whole shebang cuts off and the engine stops. If the alternator circuit shorts, it kills the charging circuit preventing a fire and does not disable the car or lose your ECU settings.

Perhaps you fail to recognize I was giving him the correct and safe answer. Rather than a cheaper unsafe way to do things. I know what isostasy is and how it applies to water. But if you want to do this safely, you have to fill your bucket with another hose, and let the water flow downhill to the components.

If you don't believe me, I really don't care. I won't argue with you except to say your setup is not safe, and you might as well not have a main breaker or fuse at the battery because it won't kill your electrical system when something shorts.

So...The battery setup from factory is wrong? You know way more than I do, but I thought the way he did it was pretty much like stock except a really long power cord from trunk to engine bay. I know that i'm not doing mine for strict track rules. But just moving the battery to the trunk for more space in the engine bay. What makes the factory way unsafe? Or is it unsafe for track purposes? I want to do this once! So I guess I'm just wondering which way will be correct.

Thanks!

 

[knochgoon24]

I'm not a plumber, I'm an engineer. I used the water example because most people understand pressure and flow, where they don't understand how the same kind of thing happens electrically. Current = flow. Voltage = pressure.

Your little animation is flawed. You fail to take into account that the battery (bucket) has the circuit breaker on it before any of the stuff in the middle and alternator (pump) has a fuse on that line before anything in the middle. To continue with the pumbing example since I'm enjoying it quite a bit now, the fuses and breakers act like a valve with a sensor. If there's too much flow (current) through the valve, it closes it. Water wouldn't flood the screen. You'd get no more than the quick trickle you'd get with your setup.

My setup would kill the power if something shorts. It's no more fire prone than yours. The alternator is run to the 100A fuse in the fuse box. The battery has a 200A breaker in the back with it. If there's a short in the main cable, both will blow. You used 2 breakers. I used a fuse and a beaker. There's only 2 power sources, so you only need 2 heavy duty current protectors; one on each line as close to the source as you can; which we both did.

Now each wire every time it branches should have a fuse on it if it's a smaller gauge than the main one. The fuse should be rated lower than the safe amperage for each wire, which both our setups do. The fuse should be as close to the split as possible for safety reasons. If a short happens in a smaller wire, the fuse on that wire will blow.

I said you don't understand DC power because you said this:

...If you put the battery on the other end of 12 feet of wire, it has to send power backwards against the current to charge the battery while the battery is sending power back to the fuse box. That won't really work.

If your alternator is outputting enough power to charge the battery, it is also outputting enough power to run all the accessories. It doesn't charge the battery as the battery powers stuff. That's not how it works. Current is only going to go one way in the wire; from the end with a higher potential energy (voltage) to the end with the lower voltage.

I'll break down if you're confused on why I'm saying you don't understand.

You won't charge your battery if you do it that way. (Yes you will.) If you tie the alternator into the fuse box up front, you're charging your fuse box, not your battery. (If there's extra power, the wires connected from the battery to the fuse box will charge the battery.) If you have a short before that point, the breaker won't kill the engine because the alternator is still powering everything through the main fuse in the fuse box (including the short upstream). It needs to stop the charging, thus preventing a fire. (That fuse that's in the fuse box will blow or the fuse for the accessory will blow.)

You have to consider the DC flow of what the + wire does. (???) The alternator charges the battery and flows from the battery to the fuse box, to the components in the car. The alternator connects to the battery with the two white wires illustrated in the pictures I posted. (IIRC, not it doesn't. There are 2 white alternator wires that run from the alternator to the fuse box, then two more white wires that run from the fuse box to the battery.) If you put the battery on the other end of 12 feet of wire, it has to send power backwards against the current to charge the battery while the battery is sending power back to the fuse box. That won't really work. (I explained this error already.) The alternator has to have a dedicated line. You have to have fuses or breakers within a foot of the battery terminals. (Good advice there.) It takes 2 wires to do it correctly. (No. Explained that.)

If you click through to the YouTube video I posted earlier, there's a more detailed description of why it needs to be done this way in the video info.

Now I watched that video, but I didn't see the detailed description of why it needs to be done your way.

So...The battery setup from factory is wrong? You know way more than I do, but I thought the way he did it was pretty much like stock except a really long power cord from trunk to engine bay. I know that i'm not doing mine for strict track rules. But just moving the battery to the trunk for more space in the engine bay. What makes the factory way unsafe? Or is it unsafe for track purposes? I want to do this once! So I guess I'm just wondering which way will be correct.

That's pretty much all I did. There's a circuit breaker on each end of that long "extension cord" from the battery to the spot where the battery used to sit up front, where another circuit breaker sits. I also upgraded the stock wiring from two 8 gauge wires to two 4 gauge wires because I had some spare wire left. Plus I'm running a 140amp alternator and an Optima RedTop. There's plenty of juice flowing in my car. All my grounds were also changed from the stock ground to either 2 or 4 gauge wire.

The battery in my car will eventually be put in a battery box, and a kill switch will be added. If your interested, it is going to be put on the wire from the battery after the circuit breaker. The alternator power will be killed by killing the fuel pump power. The engine quickly sputters out from having no fuel and the alternator stops spinning, thereby killing power from it. Others have also set up their kill switches this way. Actually, I'd rather have that extra gas burned inside the engine for an extra second or two instead of being inside the engine bay in a pressurized line with an engine fire.

Sorry I'm so wordy or confusing. I'm much better at explaining things in person.

 

[Jafro]

They got pills to fix spastic.

They got pills to fix crazy.

There is no pill to fix stupid.

 

[knochgoon24]

Your main breaker doesn't have to kill everything. Unless you're wanting to use it as a pseudo-kill switch I don't see a reason why it should need to. That breaker isn't going to pass tech as a kill switch. No one is going to pop your trunk and kill the power with it in a wreck if you're unconscious. I just don't see your safety argument. Instead of running 1 live wire though your cabin, it seems like you're running 2.

I've never messed with a 1g. If they have grounding loop problems that's news to me. And I don't see how your way of wiring it would fix any of those problems.

And where exactly will my setup cause a fire? What wire is unprotected? If that long wire between the battery and the engine bay side chaffs through, a breaker will blow. The alternator fuse would blow too.

What track do you race at that requires a kill switch on a relocated battery only after a certain speed? All my local tracks require a kill switch on any relocated battery, at any speed.

 

[Jafro]

yawn

 

[knochgoon24]

If you're an engineer, you should know a few things.

a) it's unsafe to put a battery in the passenger area of any car that's not in a vented-through-body sealed fire-safe enclosure. Gel-cell or not.

b) an alternator DOES NOT HAVE A GROUND WIRE (see your re-draw of my illustration above).

c) you'd better get which bolt on the fuse for the alternator wire correct or you could have no protection whatsoever.

d) I'm both a Georgia College grad (BSE '94) and have a specialization in fluid dynamics from Georgia Tech ('96). My car is in the 12's full-weight and everything works. I joined this board in '03 but owned it since '01. I've been fixing cars since '86. If you wanna argue, fine. Argue all you want. But until you get your car out of the 14's and follow safety regulations for battery relocations, I don't really care what you're saying. When you "break a pipe" with a short on an electrical circuit, direct current indeed flows, and is directional. It exits at the point of least resistance... so stop arguing that "pressure" point telling me I don't know because my statement is 100% correct where safety is concerned.

e) your method doesn't work on a 1g.

f) lets both trip our main breakers with the engine running and see if the car dies.

EDIT: "Your main breaker doesn't have to kill everything." It's not for track officials. It's in case of catastrophic failure where there's a severe accident that doesn't kill the motor. Any shorts in the main (in the event of twisted metal and wires) kills the main breaker. End of fire hazard. It's so simple I have no idea why you don't get it.

a) I said that it should be in an enclosure. That's why it won't pass tech without being in a box. No argument there.

b)I ran 2 ground straps off my alternator case. There's a stud there to use one. One is run to the frame an one to the engine block. Right now, your alternator is grounded through its case to the engine block. It has to be grounded some how.

c)It's correct. Might not have drawn it perfect on that picture though. The whole engine bay side of my wiring is just like it was stock. The only difference is that in place of the battery terminal, there's a bolt for everything to connect to on the circuit breaker.

d)Congrats. Bringing the "how fast is your car" argument into things. Too bad that time's a year old. The car now runs the 16g @ 23psi and has another $1000 in other parts. Should make for a slightly better time. You couldn't run your car at the track I run at the way you have it set up now anyway. You'd need a kill switch. The only reason that current will flow is because the two spots are at different voltages. It's directional. The direction is all based on whether you want to follow a system where electrons flow or the "positive charge" flows.

Oh, and I'm an aerospace engineer. Aren't fluids just so much fun? I had a bunch of those electromagnetism classes too. I though about going to Georgia Tech, but the weather is just too warm down there for me, so off to PSU I went.

e)I don't see how yours would make a difference. You're still grounding your battery in the trunk.

f)I wouldn't expect mine to. It's not a kill switch, nor do I intend to use it as one.

BONUS ROUND: My car wrecks. It's a pile of twisted metal. Power from the battery is cut by the circuit breaker in the back. Power from the alternator is killed by the alternator fuse in the fuse box. The car still shuts off.

If the wire that shorts isn't one of the two main wires you have run, it's going to be the accessory fuse that blows, and the engine will continue running if that circuit wasn't critical. Nothing different happens compared to yours except I'll have to replace a fuse.