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BamaNomad
07-31-2017, 09:17 AM
I'm coming to the conclusion that I will likely have to install the battery in the rear of the '57 Nomad that I'm building.. and I have some questions that some of you have experience with and might help?

1) For the typical rear mounted battery in a '57 wagon (Nomad), how long will the battery cables need to be? Is 10 ft sufficient to get from the starter solenoid (or an LS engine) to the rear of the RHS wheel well??
2) What size cable (stranded copper I assume) is needed to support the current required with minimal voltage drop? Is 2 gauge sufficient?
3) Is it necessary to run both pos and neg cable from the engine compartment to the battery? Or can the frame be used for the ground/return??

The last time I did a rear-mount battery was in 1971 when I did so in a Henry J I was building, and I used '00' welding cable, which was likely significant overkill... https://www.trifive.com/forums/images/smilies/smile.gif Any suggestions/help is appreciated.

55 Rescue Dog
07-31-2017, 10:11 AM
I would go with 1 gauge which would have less resistance, with the same size to the frame for the ground, and a disconnect switch. And a good braided ground strap from the frame straight to one of the starter bolts. Yes, steel has more resistance than copper, but the frame of the car is a pretty large conductor. I fed my positive cable into 1/2 in air hose for more protection, since the insulation on most battery cables is not that robust for routing the cable through or under the car. For a little more money you can get a remote battery disconnect operated by a toggle switch, or even one with a wireless anti-theft remote disconnect.

Bitchin'57
07-31-2017, 11:54 AM
1/0 is what I'm going with.

chevynut
07-31-2017, 12:45 PM
I bought a rear-mounted battery kit from AAW (with side post connections) and I believe it's 1 gauge. I think 1 gauge or 1/0 is sufficient. I'm using the frame for the ground conductor. Just make sure you make a good connection at each end, and ground the body to the frame....I did it at both ends.

markm
07-31-2017, 01:01 PM
One of those things that bigger is better.

WagonCrazy
07-31-2017, 02:57 PM
I'll try to get you a comprehensive answer on what I've done in my LS Nomad in a day or two. Need to snap some pics and post how I routed it...

chevynut
07-31-2017, 03:33 PM
Bigger is better up to a point...beyond that you're just wasting money. Copper has gotten really expensive and it didn't use to matter how big you went, but nowadays it's costly to go overkill. The large cable isn't needed for anything but cranking. A small voltage drop isn't going to hurt anything, especially with today's gear reduction starters. You'll even get a voltage drop with 3/0 cable....the question is how much is too much.

Rick_L
07-31-2017, 04:03 PM
Quality connections are as important as the wire gauge.

55 Rescue Dog
07-31-2017, 04:49 PM
Quality connections are as important as the wire gauge.
Exactly! It is actually more important, and something that needs to be checked, and maintained for sure. I love OHM's law!

BamaNomad
07-31-2017, 09:55 PM
I really appreciate all your comments and suggestions; all of which will be considered carefully before I make my choice;

Wagon Crazy.. I'd really like to see details of what you did also..

Bitchin'57
08-01-2017, 12:09 AM
Quality connections are as important as the wire gauge.
This place has a lot of good parts.
http://www.cloudelectric.com/

WagonCrazy
08-01-2017, 08:08 AM
Here's what I'm doing for a rear mounted battery in a 57 Nomad:

The battery is mounted behind the passenger REAR seat, in a yet-to-be-fabricated bulkhead that will extend across the full width of the back seats, and provide some storage room for battery, stereo amp, speakers, tools, cleaning stuff for shows, etc.

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The cable is (I think) 1 ott stranded cable. I bought this at an automotive swapmeet...about a 16 foot length for about $75 if I remember correctly.

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The cable will run from the battery thru the bulkhead sheetmetal (hole and grommet to be installed when fabricated), then on top of the floor, over the center of the driveshaft sheetmetal.

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It wil run UNDER the PCM (mounted on the driveshaft sheetmetal hump between the seats...to reside at the bottom of the yet-to-be-fabricated center console) and then to a DISCONNECT switch which will be mounted inside the yet-to-be-fabricated center console. Out of sight of casual observers.


continuing with another post....
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WagonCrazy
08-01-2017, 08:20 AM
it continues on from the switched side of the Disconnect Switch to a "thru firewall style" connector punching it thru the floor on the "passenger side" of the transmission underneath.

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From that point, a "battery source" wire runs thru a 300amp circuit breaker that feeds ALL electrical needs (main fuse panel, addl. fuse panels and 12 volt "keyed" source, etc).

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Once on the underside of the trans tunnel sheetmetal, it runs forward towards the starter (almost a straight shot).

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Where it comes up next to the solenoid and attaches to the post with a heavy lug "bent 90 degrees". It's protected from the header heat by a thermal resistant style spark plug boot.

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All told, there's about 8 to 9 feet of cable here. The main reason for not punching it thru the firewall (instead of the floor) is that the cable is so heavy that it wouldnt make the bend to get around the back of the block to the starter solenoid. So I chose the more straight line shot by punching thru the floor (trans tunnel) at the appropriate spot based on all the other stuff going on here...

When done, this will be mounted down tight every 18 inches or so, will be fully protected from any sharp edges (abrasion) and hopefully...is so friggin much copper that I never have an excessive amount of resistance when cranking the engine...

As Laszlo said earlier, there comes a point when it's overkill. I've probably done that here, but better to err on the side of caution. I've had "hot start" problems with other tri-5's when headers and SBC solenoids were involved. So I'm attempting NOT to have to go to a remote solenoid on this build...just use the stock LS1 starter/solenoid as it was designed.

Here comes the questions...Ask away...

chevynut
08-01-2017, 01:02 PM
I checked AAW's catalog and all of their trunk-mount battery kits use #1 size cables.

BamaNomad
08-02-2017, 05:47 AM
1 gauge seems to be the consensus from all the posts that have been made, and from the reading I've done (without going overboard).. :) #2 'might' work most of the time, but it seems #1 would work fine for almost all situations (at least as good or better than factory type systems).

Wagon crazy: Are you using an AAW wiring kit and fuse panel??

WagonCrazy
08-02-2017, 08:17 AM
The fuse panel is an EZ Wiring 18 circuit one. And I've swapped out a few of the unused fuse positions for other stuff I need. It's a basic wiring harness...has the wires heading towards the dash and another set heading toward the back of the wagon.(typical of all tri 5 harneses).

And I've added some more fuses for the LS circuits (coils, injectors, and a few other "keyed ignition" circuits that need fuses).

Bama...are you installing an LS engine? or old school SBC/BBC?

For LS wiring harness modifications, I found an excellent youtube video series of a guy wiring up an offroad Jeep. Most everything he shows covers a typical hot rod engine swap too.

Maybe I should start a new thread under this Electrical forum for my LS engine wiring...

BamaNomad
08-02-2017, 09:18 AM
I have an LS1 with the 4L60 trans (from a 2001-2 Z28). I have some information that Rockytopper sent me a while back re 'rewiring' from the stock factory kits, but I haven't yet attempted any of the rewiring. My *plan* (so far, or maybe HOPE is the better word) is to attempt to retain the factory Z28 setup for the engine/trans control thru the factory computer. I think the weight of my 57 Nomad will be similar to the Z28, and I've got a 3.08:1 rear gear with similarly sized tires. I have a local acquaintance whom I can call on (ie. pay for his hours) to assist me with rewiring, but for my own satisfaction, knowledge and understanding, I'm hoping I can figure it out and do it on my own...

I've purchased an AAW Wiring kit, but haven't gotten to the wiring stage as yet... still trying to get an overall plan in place before I begin.. :)

WagonCrazy
08-02-2017, 11:12 AM
still trying to get an overall plan in place before I begin.

Begin with the end in mind...that's the hardest part because you will be educating yourself as you go.

I'll start a new post on the wiring of my Nomad soon. I've not wanted to share much because I've made some mistakes and it goes slow when you go back and correct things, but I'm getting to the point where my confidence in what I'm doing is coming way up. So time to share and get grilled by y'all. :p

chasracer
03-03-2018, 05:51 AM
I have used 0/2 welding cable for years on a variety of car builds. It's slightly smaller than the #1 cable making it a bit easier to deal with under the car and tight spaces. Connections have always been copper terminals that are soldered and then covered in heat shrink tubing. The cable can be sourced locally or online a bit cheaper.

NickP
03-03-2018, 06:42 AM
I'm no electrical xpurt but it seems to me that every "+" connection, regardless of it's path from the storage cell to the starter needs to be spot on but more importantly, accessible. The fewer the better I think. I recall this place used to have components for this task: http://www.madelectrical.com/