Mounting battery in the trunk questions, electrical questions...

[johns cuda shop]

I was just wondering if 400 amps would be enough, or if in some conditions, starting might trip the breakers....as I said above, there are a lot of variables.  I would like to think that is large enough, but, ??

I have seen some starters that pulled more than that for an instant...

Google offers a variety of opinions from no way to works for me on the circuit breakers

Our starters normally don't seem to pull as much amperage because they are gear reduction instead of direct drive so it takes less current to turn them over.

An alternative, which I think has been mentioned, would be to put a solenoid in the truck and trigger it with the normal yellow wire from the ignition switch.  That way the battery cable would not be hot except when starting.  Then run a 6 ga wire to the battery from the alternator using a fusible link, maxi fuse, or circuit breaker on it in case it got shorted.  Might be easy to run it thru the interior so that the likely hood of it getting cut were close to zero.

I'm  Running the ISIS muliplex system wiring does not require me to use a starter relay or remote solenoid , it is wired directly from the ignition switch to the starter.. After talking to customer support at ISIS , They told me 2 200 amp circuit breakers is more than enough for the starter draw. Another thing he mentioned is I should run a 2/0 cable for the charge lead instead of the standard 4/0 that I was going to run, because of the electric radiator fans will experience some voltage drop at idle because the alternator puts out less while idling at the 4/0 size and the 16 ft or so of distance,plus all the other accessories I am adding .He also said to use a stud instead of a self tapping screw screwed into the same frame rail the alternator case is grounded so it eliminates any problems.

[brads70]

I'm  Running the ISIS muliplex system wiring does not require me to use a starter relay or remote solenoid , it is wired directly from the ignition switch to the starter.. After talking to customer support at ISIS , They told me 2 200 amp circuit breakers is more than enough for the starter draw. Another thing he mentioned is I should run a 2/0 cable for the charge lead instead of the standard 4/0 that I was going to run, because of the electric radiator fans will experience some voltage drop at idle because the alternator puts out less while idling at the 4/0 size and the 16 ft or so of distance,plus all the other accessories I am adding .He also said to use a stud instead of a self tapping screw screwed into the same frame rail the alternator case is grounded so it eliminates any problems.

Good to know thanks! I'm a little puzzled by what he told you on the wire size though? 4/0 is bigger than 2/0? I just bought 20 feet of 3/0 It sure is huge wire about 5/8" on the outside.

[Strawdawg]

4/0 is larger than 3/0. . Or 0000 is larger than 000.  I think he got it backwards

[dodj]

Bigger wire will be better, but I sure wouldn't run the size wire that you guys are talking about. 
#2 would be the biggest I'd go. Going into the 'ought' sizes is way overkill imo.
The voltage drop over the length of a car is ridiculously small. It's the connections you need to worry about.

[HP_Cuda]

Strand size, single strand vs multi-strand, and then connections will make a big difference in (R).

The lower the number the larger the cable until you get into /0 cables then it goes back up. I would think that a #2 should do it as the amp spikes will only be when you start the car. At 7 to 10 feet you can easily do 200A.

Check this chart here (Gotta love sterophiles) :
http://www.crutchfield.com/S-z1SkyWEaRgK/learn/learningcenter/car/cable_gauge_chart.html

[brads70]

Strand size, single strand vs multi-strand, and then connections will make a big difference in (R).

The lower the number the larger the cable until you get into /0 cables then it goes back up. I would think that a #2 should do it as the amp spikes will only be when you start the car. At 7 to 10 feet you can easily do 200A.

Check this chart here (Gotta love sterophiles) :
http://www.crutchfield.com/S-z1SkyWEaRgK/learn/learningcenter/car/cable_gauge_chart.html

I went by this chart from the company I bought the alternator from.....
http://www.qualitypowerauto.com/Wire%20Sizing%20Chart%2012V%20DC.htm
Funny so much difference huh?  It won't hurt going bigger other than weight and expense.

[dodj]

  It won't hurt going bigger other than weight and expense.

Definitely won't hurt going bigger. But one issue I had when putting my battery in the trunk (It's back up front now) was getting a lug for the starter that would fit #2 wire. You may have to do some searching to find a lug for 3/0 that will have a stud hole the proper size and overall small enough to fit the small confines around your starter.

[brads70]

Definitely won't hurt going bigger. But one issue I had when putting my battery in the trunk (It's back up front now) was getting a lug for the starter that would fit #2 wire. You may have to do some searching to find a lug for 3/0 that will have a stud hole the proper size and overall small enough to fit the small confines around your starter.

I stumbled across this place  http://www.traction.com/en/home.html  It's 5 minutes from my house.
They had everything I need, battery clamps to the 3/0 cable and connectors going down to a 1/4 hole

[dodj]

I stumbled across this place  http://www.traction.com/en/home.html  It's 5 minutes from my house.
They had everything I need, battery clamps to the 3/0 cable and connectors going down to a 1/4 hole

You southerners have everything close by!! The only thing I have within five minutes of my house is spruce trees, bears, partridge and deer.

[brads70]

You southerners have everything close by!! The only thing I have within five minutes of my house is spruce trees, bears, partridge and deer.

Well when it all hits the fan I'm moving in with you! At least I could eat.   

[HP_Cuda]

 

Mount her up!!!

I went by this chart from the company I bought the alternator from.....
http://www.qualitypowerauto.com/Wire%20Sizing%20Chart%2012V%20DC.htm
Funny so much difference huh?  It won't hurt going bigger other than weight and expense.