Benefits of multiple runs of power front to back

[ManzKea 152]

Got a quick question. What does multiple runs of power cable front to back do? Does it increase voltage or help handle the amount of power being pulled from your rear battery back? I ask because  I’ve had the fuse holder near the front battery melt a while back.  Everything has been good for the past few months. And this just happened. So I cut off the melted part of the wire and put a new fuse holder in.   And recently it’s done it again.  

Ive read that maybe the wire can’t handle the heat or whatever so it starts to melt. Will multiple runs of 1/0 awg help with this problem or would it be wise to just run a 2/0. 

 

My my system consists of a second battler in the rear. And connected to that is a 2000 watt hifonics 4 channel amp and a 10k taramps amp. 

Thanks for any Input guys 

[j-roadtatts 1,129]

The second run of wire allows more amperage/current to pass from one point to the other.

Its called ohm's law and is a simple triangulation between volts=amps=watts. 12,000 watts/12 volts= 1000 amps. @14.4 volts you get 833 amps being drawn.

 As you see more of one unit directly results in less of the other. Same thing that occurs in an amplifier when presented an 8 ohm load instead of a 4 ohm. half the ohms, twice the current available on the same voltage!

Now we go to a wire gauge rating chart. 1/0 ga. is rated for 250 amps up to 12' distance. Being you have 2 batteries and the one is hooked directly to the amplifiers, you can cut the amp draw in half. So if your run is 12' or under you should be perfect with a second run of 1/0. 

If you were competing you would want the alternator to produce the 833 amps @14.4v, and would need wire rated to pass that amount from alternator all the way back. For a daily this is not necessary. Let me put it this way, if your alt is only rated at 250 amp's there is no need to run a bigger than 1/0 wire from it to the battery(s). What you are trying to accomplish is move the alternator + front battery current to the rear. 

[ManzKea 152]

32 minutes ago, j-roadtatts said:

The second run of wire allows more amperage/current to pass from one point to the other.

Its called ohm's law and is a simple triangulation between volts=amps=watts. 12,000 watts/12 volts= 1000 amps. @14.4 volts you get 833 amps being drawn.

 As you see more of one unit directly results in less of the other. Same thing that occurs in an amplifier when presented an 8 ohm load instead of a 4 ohm. half the ohms, twice the current available on the same voltage!

Now we go to a wire gauge rating chart. 1/0 ga. is rated for 250 amps up to 12' distance. Being you have 2 batteries and the one is hooked directly to the amplifiers, you can cut the amp draw in half. So if your run is 12' or under you should be perfect with a second run of 1/0. 

If you were competing you would want the alternator to produce the 833 amps @14.4v, and would need wire rated to pass that amount from alternator all the way back. For a daily this is not necessary. Let me put it this way, if your alt is only rated at 250 amp's there is no need to run a bigger than 1/0 wire from it to the battery(s). What you are trying to accomplish is move the alternator + front battery current to the rear. 

Thank you for the very in depth response. Looks like I know what I’ll be doing this weekend. 

[Travis 82]

First off, I would like to note, one of the easiest ways to sustain higher voltage and it reflecting on the dash is runs of power wire. (given all grounding is on par) A local and prior world champ who was part of TEAM DB DRIVE was running 10k RMS in his van. One day he decided to do runs of power wire front to back (from the heart of the electrical system, under the hood) until he quit getting gains on the meter. On that 10K rms setup he stopped getting gains on the dash at 32 runs of wire, yes thirty-two runs. Due to being able to transfer power with nearly no resistance, he gains tenths of volts which turned into tenths of a DB, he finally found the end the possible gains using only power wire. Cool read I found. But only if you're doing something such as what he was trying to accomplish. 

[j-roadtatts 1,129]

Resistance=Heat

The question really is how long? How long will a low note being played at full tilt CONTINUALLY take to overheat the amplifier internals. How long will said amp last in such conditions. Not very, and that's why comp guys are rough on amp's. On the other hand, music is dynamic. The amplifier will not see those conditions. Also you are only moving the hot spot to the next weakest link, which is the alternator. That's why comp guys be running 4+ of them.

 Heat (resistance) is an electrical device's worst enemy. For every 10 degrees Celsius the life span of the internal components is cut in half. I can only imagine how much you are shortening the lifespan of your amplifiers with the way you have it wired now. If you want to be real technical, the electrician rule of thumb is only run wiring to 80% of its rating. So figure out how long your run of wire is and add 20% to the total amp rating for comfort... If you want to get technical.

[altoncustomtech 773]

Lots of great information here. I couldn’t agree more with anything said. 

 

 

[Aaron Clinton 2,372]

Great posts Jared.

[Tirefryr 1,742]

A lot has been said, but don't forget about connections.  Poor connections are the number one source of heat due to increased resistance.  This can be as simple as a loose screw, poorly crimped terminal, or a bad solder joint.  Always use the proper tools and techniques and re-check your connections often.  Keep in mind, you have so many dissimilar metals and this is THE recipe for corrosion. 

[Travis 82]

Agreed. Bad grounds can do major damage also. And things can vibrate loose. I lost ground years ago on my first mtx 2300 back in the day. Caused the amp to catch fire. 

Edited February 21, 2018 by Travis