How to fuse multiple runs of power cable

[shizzzon 461]

Ok, i've never ran multiple and have come to a barricade here so fill me in.

1 battery up front, 5 batteries in the rear.

400A for bass, 90A for mids\highs.

Total Amperage fuses needed- 490A ~ 500A.

Ok, first off-

I'll have 3-4 runs of 3/0 wire going from front battery to rear battery bank.

Right now, i just have 1 3/0 wire ran which is fused with ANL fuse and no fuse at other end because everything is dismantled right now.

With 3 runs, i was going to attempt to use a bat terminal that had 3 1/0 connectors on it.

I run the alternator to one of those leaving 2 left. The factory electrical wiring goes into the other slot leaving one left.

I'm assuming i'll use a distro block with reducers to run 3/0 to 1/0 reducer into terminal, the other end runs into a distro block...

In between the terminal and distro block is where i put a fuse holder in....

I CANNOT FIND 500A FUSES! from car audio industry.

I have found one... only one and it's ANL actually but main purpose is for gas powered boats with large battery banks.

It's on ebay so who knows how much longer it'll be available especially if i ever needed another one.

There's one problem...

2nd-

Once all these runs reach the rear battery bank, is it ok if i rerun all 3 wires into 1 3/0 wire using distro block, fuse it with unknown fuse then let it go to battery bank?

Purpose is to get lowest voltage drop possible but with properly fusing at every point.

Also, when i ground all 5 batts in the rear, should i ground each battery to ground rather than just have 1 master ground off the bank?

[audio-neon 34]

Use division, If you are running 3 power, use 3 160 amp fuses.

[shizzzon 461]

i had thought about that, but am unsure on the "real world" scenario of doing that.

One of the 3/0 wires is different than the other 2 so it will have the capability of pulling more\less than the others.

Also, i was unaware if splitting wires like that would actually divide the current up exactly like you say it would.

What prevents one of those wires from "trying" to pull the full 500 at a time? that's what i do not understand.

Also, if one of those 3 fuses pop, the other 2 should pop relatively quick. IS it possible that before the last fuse pops that the wire could burn\melt or catch fire before fuse pops?

Edited April 19, 2008 by shizzzon

[creyc 1]

If your battery bank is in the back by your amplifiers (I'm assuming) then why 3 runs of 1/0 to the front? Just for charging? Seems silly to run so much wire to the front since your amps and batts are all in the back.

At any rate, one run of 1/0 power wire should be sufficient to carry the current from your alt to charge the bank in the back. I wouldn't fuse this at 500A, since even under full load your amps should be pulling power from your (closer) battery bank in the back.

Now with a H/O, or multiple alternators or multiple batteries up front, this all changes. I would personally leave the front battery almost alone, for the rest of the cars electrical needs.

[shizzzon 461]

i have to use the one up front to finish the requirements of batts needed to run this setup.

I'm only gonna have 5 hc600s in the rear. I have an hc1800 up front, which u see is needed for my setup.

Oh and with a 300A alt too.

And there are 12v fuse terminators in this install as well. I "could" use them as my actual in line fuse holders for my multi runs of cable. This would also prevent my batt up front from dropping below 12v while driving to allow me to start the car again.

Multi runs of cable is used to have the highest voltage possible by the time it reaches the batt bank in rear.

Edited April 19, 2008 by shizzzon

[shizzzon 461]

ok, rockford fosgate carries 500A fuses.

So...what should i do.

And i got the actual wire specs-

1 wire is stinger's 3/0 wire.

The other 2 wires are knukonceptz kolossus wire 1/0.

That's the problem with attempting to fuse each line... the stinger line will pull more current.

[Adrian_D 520]

Considering 1/0 is rated for about 300A, I would use the 3/0 from front to rear and use 1/0 for the rear...

I don't see any point in going with 3 runs of wire from front to rear because you only have one 300A alt and a single battery.

Even if you do run the stinger and the knu 1/0, the stinger will not pull more current. It will be able to cunduct more current, which is a whole diffrent thing.

From my knowledge, fusing in the front is done to protect the actual wire in case something happens along the run and it touches the car. So, basically, you fuse at the amount of current the wire is rated at. You will also need fuses in the back, for the same measure of precaution.

For protecting your amps in case something happens, you would need to fuse each amp before its terminals and this is the place where you need to take into consideration the consumption of each amp. (If something blows in the amp, you can get to the situation where the power supply of the amp blows and it's going to act similar to a short-circuit on the positive and negative wires. The faster you stop supplying current, the less damage will be done)

Considering you are not using more current than the wiring is rated for and you have perfect connections, in every point of the system you will see the same voltage.

Take a look here for some more details on the wires and their load capacities :

http://www.powerstream.com/Wire_Size.htm

[shizzzon 461]

Thank you for that detailed response.

The reason I keep mentioning multi cable runs is because the more cable u have, the high my voltage will be.

Like on a wire calculator-

Using a single 3/0 wire compared to 3 2/0 wires is almost a full volt difference.

So, if I drop 1.6v using 3/0 but only drop 0.5v using 3 2/0, shouldn't I do multi runs?

I know calculators don't take into account that the wire will eventually reach another battery bank which keeps voltage up... But this is mainly so the alt's voltage stays high enough so it doesn't dip into the batts.

Isn't that how it's suppose to be?

[Adrian_D 520]

You will first use up the batteries and then dip into the alternator.

Also, I believe those programs do not take into account the fact that you have 5 batteries in the rear of the car

Not sure how they came up with a 1 volt diffrence in the example you posted...

A "better safe than sorry" option would be to do 2 runs of 3/0, if you can find enough to suit your needs

Do you plan on competing ?

[shizzzon 461]

No, i do not plan on it but this is what i do know-

I do not know exactly what the float voltage is of kinetik batteries but whatever it is, the voltage right before the battery better be quite higher than the batts voltage itself.

IF it isn't, the alt will never charge the batteries.

Now, if the voltage is significantly higher than the float voltage, then all current draw will be supplied via alternator. Quick spurts of current would come from the batts because voltage regulator wouldnt react quick enough for that.

I used that calculator from the website you posted.

However, i'm trying to find a different calculator to see if i can get better results, dont like theirs, hehe.

[shizzzon 461]

ok found another calculator.

It doesn't take into account the maximum amperage a wire can handle before it catches fire but this is what this other one says-

if 490A were to pass through single 3/0 wire at 18ft, voltage drop would be - 0.662 volts. measured resistance 0.0013 ohms.

But, when fusing from battery to battery, i pretty much just fuse by wire capability or alt rating?

So, i'd use 300a or smaller in between batt up front and batt bank in the rear, correct?

Then from the batt bank in the rear to amps, each amp is fused externally with regular 1/0 wire.

Since i can keep wire short there, voltage drop is very minimal.

One other thing also-

When grounding all 5 of these batts in the back, i take it it's wise to not only have all batts in parallel but also try and ground them all individually as well for best ground possible?

[shizzzon 461]

well, let me ask this-

Do you think with these batts and 300a alt that i'd be fine running 4kw bass and a sundown 100.4?

I'm assuming that the bass part will be too much to handle for consistent durations anyways since i've never done anything this loud before.

If you guys don't think this is enough electrical, i'll back it down to 3kw of bass, but i think 4kw is doable as long as i don't prolong it.

[Adrian_D 520]

If you won't run it a long time with the engine off, I think it's going to be ok for 4kw.

[shizzzon 461]

i've never done that, never trusted a setup like that.

If i ever show off when i'm parked, it's either car is on or if off, not turned up that loud at all.

OK, you've helped out a whole whole lot, thanks.

[Adrian_D 520]

You're welcome man. That's why we're here for