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    Results 1 to 17 of 17
    1. #1
      Join Date
      Sep 2016
      Location
      Bakersfield, CA
      Posts
      603
      Country Flag: United States

      Help with my battery relocation please

      1969 Firebird. First off, I'm really a dumb simpleton and a total newb when it comes to electrical, so when helping PLEASE spell it out for me like I'm a child. I need to get my sh*t in order before my car burns down. I want to do everything right (correcting what the previous owner did) and the first step in that will be relocating the battery to my trunk behind the rear passenger seat (I need the space under the hood).

      I have read the battery relocation sticky and it helped tremendously to get me this far. Now I just need to tweak it for my setup.

      I'm running a ton of modern stuff that needs GOOD power: Dakota VHX gauges, Dakota digital fan controller, dual electric radiator fans, VintageAir A/C & heater, fans on my transmission & oil coolers, LED headlights & all LED bulbs everywhere else all over the car, Holley Terminator Stealth EFI & fuel pump, and eventually I'll add a mild stereo system. Also, I live in the CA desert where it can be 125F, stuck in traffic, with literally ALL of that running simultaneously. Only thing I don't have is an electric water pump and power windows.

      Here are the parts I already have:

      New 1 wire alternator (replacing my externally regulated alt) - already installed
      Odyssey battery, NHRA Moroso battery box w/pad (NHRA)
      Pollak battery disconnect switch (NHRA) w/pigtail to keep power to the radio - mounted on tail panel
      Remote starter solenoid - currently on the radiator support
      New ground cables: Battery to the body, body to engine, & body to the radiator support. All are 1/0 gauge in black.

      My buy list:

      Power distribution block
      200 amp fuse
      3/8" bolt hardware to mount battery box
      4 gauge welding wire

      Currently, the previous owner has installed a starter solenoid as a distribution block on the radiator support on the driver's side. Alternator wire goes to it, from it goes a wire to the battery and another to the starter (2 other small wires too). The electric fans have relays and fuses but are wired to the battery instead of this solenoid/distribution point for optimal alternator amp draw like I think they should be.

      I plan on relocating the solenoid to use in the trunk by the battery, so I'll go battery + to the solenoid. I've heard that doing this is great because then the big cable going under the car to the front is only energized during starting. Correct? Where is the best place to put the fuse for the system?

      I then plan on installing a proper distribution block on the firewall where the external voltage regulator currently is. Then I'll wire the alternator to the distribution block. To this distribution block, I'll connect the electric fans and main power for the fuse box. From the fuse block, I have my digital gauges, fuel pump, etc. wired. My Holley goes straight to the battery + as instructed.

      My questions:

      1): Wiring the solenoid so the cable going up front is only hot during crank. How exactly? I have attached a picture of it. Like what cables from where should go to which terminals on it?
      2): Wiring up the starter. How exactly? From where to where? I'm not exactly how this work with a remote solenoid.
      3): Wiring in the disconnect switch. How exactly? I have attached a picture of it. Like what cables from where should go to which terminals on it?
      4): I have ZERO clue how that pigtail on the disconnect switch wires so my radio remembers it's presets, but I figure I'll cross that bridge when I upgrade my stereo lol.

      Once I can get a diagram drawn up for my exact configuration, then I can order the cabling, connectors, tools, and other parts I need to start going to town. I've decided to invest in a heat gun and crimpers and learning to do it all myself.

      Thanks!!!!
      http://www.TheFOAT.com/92GTA
      1969 Pontiac Firebird
      w/535ci IAII aluminum block, Dailey dry sump, Holley EFI (full road race build). Primer black w/black interior.
      1992 Pontiac Trans Am GTA w/SLP Performance Package. Dark Jade Grey Metallic, grey leather, T-Tops.

    2. #2
      Join Date
      Sep 2016
      Location
      Bakersfield, CA
      Posts
      603
      Country Flag: United States
      Thanks for some help on Camaros.net I went with the diagram that's attached.

      I'm stoked, got everything ordered I need down to every last part except the fuse.

      I have a mega 320amp alternator that can do 180amps@idle to power everything, it works great so far! What size of fuse do you think I should use where it shows fusible links in the diagram? I went with 4 gauge welding cable for the negative stuff and 2 gauge for the positive stuff.
      Attached Images Attached Images  
      http://www.TheFOAT.com/92GTA
      1969 Pontiac Firebird
      w/535ci IAII aluminum block, Dailey dry sump, Holley EFI (full road race build). Primer black w/black interior.
      1992 Pontiac Trans Am GTA w/SLP Performance Package. Dark Jade Grey Metallic, grey leather, T-Tops.

    3. #3
      Join Date
      Dec 2010
      Location
      Fredericksburg, VA.
      Posts
      3,155
      Country Flag: United States
      Spend some time reading the Tech articles on MAD Electrical. The very first thing I would do is convert the one wire alt to remote sensing. The one wire is not the best choice, a good remote sensing alt setup is much more effective. I'm running a 190 amp 10SI style three wire alt and have never had an issue. Again this topic is discussed on MAD Electrical. The wiring diagram you have above is from MAD and that is the way he recommends wiring a trunk mounted battery. But you still have a hot wire running the length of the car. IMO the trunk mounted solenoid approach is overly complicated and has more points of failure. Personally, I run a single 1/0 cable from the trunk mounted battery positive terminal to a trunk mounted 250amp circuit breaker and from that circuit breaker to the positive terminal of the starter. Yes my main cable is hot all the time but in the off chance it were to short it would simply trip the circuit breaker. K.I.S.S!

      http://www.madelectrical.com/electrical-tech.shtml
      Steve Hayes
      "Dust Off"
      68 Camaro

      Given sufficient initial acceleration, even pigs can fly!

    4. #4
      Join Date
      Sep 2016
      Location
      Bakersfield, CA
      Posts
      603
      Country Flag: United States
      Quote Originally Posted by TheJDMan View Post
      Spend some time reading the Tech articles on MAD Electrical. The very first thing I would do is loose the one wire alt. They are not the best choice, a good remote sensing alt setup is much more effective. Again this topic is discussed on MAD Electrical.

      http://www.madelectrical.com/electrical-tech.shtml
      I appreciate the advice! I thought the same, but the vendor (Quality Power) said that was an old school problem that 1 wire alternators had and that it's not an issue anymore and certainly not on their Mega amp GM alt that I bought ($500, 320amp max, 180amp@idle, billet housing). They said if I'm going from an external voltage regulator, there is just no point in doing the 3 wire unless I have a BATT idiot light on my dash, which I don't since I have Dakota Digital gauges. They assured me this would be the way to go and I'm trusting them. Besides, it's already installed and seems to work just fine.

      I went with Bussman 250amp bolt-in fuses and holders.
      http://www.TheFOAT.com/92GTA
      1969 Pontiac Firebird
      w/535ci IAII aluminum block, Dailey dry sump, Holley EFI (full road race build). Primer black w/black interior.
      1992 Pontiac Trans Am GTA w/SLP Performance Package. Dark Jade Grey Metallic, grey leather, T-Tops.

    5. #5
      Join Date
      Jun 2006
      Posts
      167
      Quote Originally Posted by TheJDMan View Post
      The very first thing I would do is convert the one wire alt to remote sensing.
      In theory I agree with you, and I use an alternator that uses an external field ground with the regulator referencing the ignition voltage. I used a 165 Amp ND alternator from a Dodge truck. In practice if you are running a large gauge wire from the alternator to the battery I would think the voltage drop would be minimal and you are not really gaining much. I guess one cold measure the voltage and see...

    6. #6
      Join Date
      Apr 2001
      Location
      Central CA USA
      Posts
      6,108
      Country Flag: United States
      MAD talks about concern over hitting the battery with too many charging amps, overheating it. He controls charging amps to the battery by the gauge of the charging wire from engine to battery. I think he recommends 8 ga wire.
      67 Camaro RS that will be faster than anything Mary owns.

    7. #7
      Join Date
      Jun 2001
      Location
      Newbury Park, CA
      Posts
      5,821
      Country Flag: United States
      ..... and Chad Ryker just had his one-wire alternator die on him over the weekend at the optima event in Las Vegas.
      VaporWorx. We Give You Gas http://www.vaporworx.com

    8. #8
      Join Date
      Sep 2006
      Location
      Anniston, Al
      Posts
      290
      Country Flag: United States
      Quote Originally Posted by David Pozzi View Post
      MAD talks about concern over hitting the battery with too many charging amps, overheating it. He controls charging amps to the battery by the gauge of the charging wire from engine to battery. I think he recommends 8 ga wire.
      David, I'm not sure how much actual testing or current measurements they have done but this is not what I have seen. From my experience the alternators I have tested do not pump out max current to the battery unless the batteries are very low and need the current.

      Granted the alternators I have tested are large 450-500 amp units used on transit buses but I believe a normal automotive alternator should operate the same. The data I have collected shows once the battery/batteries are fully charged they will stop taking current. I used a data acquisition system with multiple current transducers, and voltage channels to see where the current was going. I also used an adjustable load bank to increase the load from 0-300 amps in 50 amp increments.

      Sorry for the rambling but my main point is you don't want to skimp on your alternator to battery charging wire size. Run a large enough wire to support the max current your alternator is capable of.
      1967 Firebird (current project)
      1967 Firebird (unfinished project SOLD)

    9. #9
      Join Date
      Nov 2011
      Location
      Wylie, Texas
      Posts
      279
      Country Flag: United States
      Actually alternators are not current pumps they simply generate a voltage that is higher than the battery voltage, but you are correct that a battery will stop drawing current when it reaches full charge. The MAD article talks about how batteries prefer a slow charge over a fast charge. A fast charge causes the battery to heat up and shorten its lifespan. So they talk about using a charging battery wire that will provide a little voltage drop across the wire when the battery is really low and as the battery charges this voltage drop will lesson so you still get a full battery charge just at a slower rate.

    10. #10
      Join Date
      Sep 2006
      Location
      Anniston, Al
      Posts
      290
      Country Flag: United States
      There's no way I would run 8 awg wire on an alternator that puts out over 100 amps. Most 8 awg wire is really only rated to between 40-60 amps depending on the type of wire. Trying to use the resistance of the wire to slow the charge is only going to turn into heat and possibly exceed the temperature rating of the wire.

      As far as charging the battery too fast goes that won't be a problem with a conventional automotive battery. A deep cycle battery does require a slower charge but I would never run a deep cycle battery in an automotive application. If someone was worried about charging their battery too fast I don't know why they would spend extra money to upgrade the alternator.

      If you upgrade your alternator to support additional accessories in your car (air ride, efi, stereo, etc) you need to upgrade all your main power leads and grounds to a large enough size that will support the max current that system is capable of. That goes for current draw or charging current, current needs the proper size wire no matter which direction it's going in.
      1967 Firebird (current project)
      1967 Firebird (unfinished project SOLD)

    11. #11
      Join Date
      Nov 2011
      Location
      Wylie, Texas
      Posts
      279
      Country Flag: United States
      The current rating of the alternator has no bearing on the charging wire gauge size. Again, alternators do no pump current into the electrical system so it doesn't matter if the alternator is 60A or 500A the battery will only draw the current it needs until it is fully charged. There will be a little voltage drop across the charging wire especially when the battery needs charging and the wire will heat up but not significantly enough to do any damage to the wire. You can certainly use a bigger charging wire and it will work but why would you want to? You don't get the benefit of the slow charging and your adding unnecessary weight and cost to the vehicle.

      If you decide to up size an alternator because you added components that require the extra current then yes you should make sure the wiring to those components have the proper wire size but the charging wire to the battery doesn't need to change.

    12. #12
      Join Date
      Sep 2006
      Location
      Anniston, Al
      Posts
      290
      Country Flag: United States
      But when the battery is fully charged and you have other accessories running the alternator does put out current to support those accessories.

      The test I performed a few months ago had a current transducer on the charging lead at the alternator, one on the adjustable load bank, and one on the battery lead at the battery.

      I fully charged the batteries before the test so when I measured battery current there was no current going into the batteries.

      After increasing the load bank to 300 amps and operating the electric fans and other accessories on the bus I measured 416 amps at the alternator output charging lead.

      When your battery is fully charged all your current for your accessories is being supplied by the alternator and you need the proper size wire to support it.
      1967 Firebird (current project)
      1967 Firebird (unfinished project SOLD)

    13. #13
      Join Date
      Nov 2011
      Location
      Wylie, Texas
      Posts
      279
      Country Flag: United States
      So in your test case you were probably using a 500 amp alternator but as you noted the current draw at max load was only 416 amps not 500 amps. The alternator only provides what the electrical system needs not the current rating of the alternator.

      After the car is started all the current is coming from the alternator, the battery is just along for the ride. It doesn't matter if the battery is fully charged or not as long as the voltage of the alternator is greater than the voltage of the battery then the alternator is supplying the current to the system.

      It's better to think of what gauge wire is needed at each node of the electrical system based on the electrical requirements of each electrical component and not based on the size of the alternator. For example you could replace the 60A alternator in a car with a 160 amp alternator and you would not need to replace any of the wiring since the individual components will never exceed 60A. Of course you would be wasting your money to do so.

    14. #14
      Join Date
      Sep 2006
      Location
      Anniston, Al
      Posts
      290
      Country Flag: United States
      For my test the alternator was rated at 450 amps but the specification or scope of the test was to prove the alternator could supply 90% of it's max rated output at a certain engine RPM. The 90% rating was actually 405 amps but the load bank I was using didn't have that kind of resolution so I got as close as I could. I would have to look back at the data but I did get over 416 amps when I was trying to adjust the loads. We could have seen max output of that alternator if the loads were there.

      Back to wire sizing, I agree that the wire for the individual components/loads would not need to be upgraded unless they were undersized to begin with. But if you are upgrading your alternator that means you are probably adding electrical components which means the main power and charging leads would need to be upgraded if they aren't rated for the may current draw of your total system.

      If you have a current clamp you can measure current at your alternator with all your loads running at the same time. Once you have that total current you can determine the minimum size charging wire you would need. Although I would make sure you have enough to support a little more than that since the battery state of charge would be unknown.
      1967 Firebird (current project)
      1967 Firebird (unfinished project SOLD)

    15. #15
      Join Date
      Jul 2016
      Posts
      341
      Country Flag: United States
      I have been using an 8ga charging wire (as recommended by MAD) for over a year now. (optima Batt in trunk) No issues whatsoever.

    16. #16
      Join Date
      Sep 2006
      Location
      Anniston, Al
      Posts
      290
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      Quote Originally Posted by DT69Cam View Post
      I have been using an 8ga charging wire (as recommended by MAD) for over a year now. (optima Batt in trunk) No issues whatsoever.
      So the only wire coming off your alternator output lug is an 8 awg wire?
      1967 Firebird (current project)
      1967 Firebird (unfinished project SOLD)

    17. #17
      Join Date
      Sep 2006
      Location
      Anniston, Al
      Posts
      290
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      https://alternatorparts.com/battery-...nator-faq.html




      Battery Wire Size and High Output Alternators

      Do I Need a Bigger Battery Wire to the Alternator?
      AlternatorParts.com - Top Quality High Output Alternator and Charging System Solutions for Demanding Situations.

      Do I Need a Bigger Battery Wire to the Alternator?
      When upgrading to a higher output alternator you should always install a larger wire between the alternator and battery. Even with a standard output alternator you will get better performance and life out of your alternator if you upgrade the main battery wiring. The original wire just isn't large enough for proper power transfer. If you are using your alternator to it's maximum output or when you upgrade to a higher output Alternator you must increase the wires size. An alternators ability to send the power it is making to the battery is directly related to the wire size and quality of connection between the alternator and battery. Also, a wire that is to small when used on a high output alternator can cause the power to back up within the alternator making it overheat, burn up and fail.

      Another area that little is paid attention to is the ground. You must also improve the ground as well. A poor ground will hinder the alternators ability to send power to the battery and can burn an alternator up just as fast as an inadequate alternator to battery wire. Your ground may be fine when you first install your alternator but over time corrosion and resistance builds up in the ground connections. This is why it is best to run the ground directly from the rear of the alternator to the battery.

      Here is another great auto electric tip from National Quick Start Sales on upgrading the wire between the alternator and battery. Randy says, you do not need to rip out your old wiring when upgrading. You can piggy back a second wire between the alternator and battery. The main battery wire connected to the back of the alternator has power to it at all times, even when the vehicle is shut off. You connect this wire like normal then you run a second wire between the alternator and battery. The power coming out of the alternator will treat the two wires as one, power follows the path of least resistance.

      On a safety note, when running the second wire you should fuse it near the battery. The fuse is just in case the wire gets pinched or shorted out, the fuse will blow instead of the wire burning up. You should use the largest fuse you can for the wire size, fuses are restrictive to current flow. Typically you want the fuse value to equal 80% of the wires load carrying capacity.
      1967 Firebird (current project)
      1967 Firebird (unfinished project SOLD)






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