Total amps (fuse) near battery

[tractng 10+ year member]

Guys,

I am looking to put 2 amps (xenon 600.1 & 100.4), which will total 140 amps. What amount (or at least) do I need at the fuse holder near the battery?

Thanks,

Tony

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[lotas 10+ year member]

Guys,

I am looking to put 2 amps (xenon 600.1 & 100.4), which will total 140 amps. What amount (or at least) do I need at the fuse holder near the battery?

Thanks,

Tony

i believe anything 150 or higher would be fine.

 

[LBX2G 10+ year member]

yup the fuse protects the wire not the amps.

 

[tractng 10+ year member]

Guys,

I am using a 4 gauge cable from the car battery to the distribution block. So 150 amp fuse is okay?

I was thinking more like 125, but both of my amps total 140 amps. Any suggestions?

Tony

 

[xSomeguyx 10+ year member]

140 will be good, 150 will be ok. The idea is to add up the amperage ratings on the fuses that should be there if there were only one. So if you had a 40a and a 60a, then 100a would be your fuse. Or if you've already got them, just put two in a row (like the 60a then the 40a on the same line).

 

[tractng 10+ year member]

Guys,

I am running a 4 gauge from the battery to the distribution block. Would 150 amps exceed the limit of the wire (protecting)?

Tony

 

[delvryboy 5,000+ posts]

it's borderline, depends on how long the run will be. honestly though, 150A should work out just fine for your app.

 

[n2audio 5,000+ posts]

Or if you've already got them, just put two in a row (like the 60a then the 40a on the same line).

If you do that they need to be in parallel, not series. In series the 40A becomes the only fuse that matters -- it's the weak link.

it's borderline, depends on how long the run will be. honestly though, 150A should work out just fine for your app.

Fuse size has nothing to do with length. The current capacity is always the same. Length only effects voltage drop.

I wouldn't go bigger than 125A, and that fuse should never blow. Maybe if you're max volume with test tones for HOURS on end.

FWIW - I'm running 1080 under-rated watts with 4 ga and an 80A agu. It runs fine. Voltage drop is minimal.

 

[delvryboy 5,000+ posts]

If you do that they need to be in parallel, not series. In series the 40A becomes the only fuse that matters -- it's the weak link.


Fuse size has nothing to do with length. The current capacity is always the same. Length only effects voltage drop.

I wouldn't go bigger than 125A, and that fuse should never blow. Maybe if you're max volume with test tones for HOURS on end.

FWIW - I'm running 1080 under-rated watts with 4 ga and an 80A agu. It runs fine. Voltage drop is minimal.

18" vs. 18' doesn't make a difference?

thats new to me...

wanna sell that 200.2 //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[tractng 10+ year member]

Guys,

Lets say, if I do upgrade the power wire to 1/0, do I have to upgrade the ground at the battery? Right now, I just left it at stock.

If I do need to upgrade the ground, whats the process? Connect a cable to the - (negative) of the battery terminal and connect to a surface (metal) of the car.

So the negative terminal will have the stock ground and my new ground wire too? Just want to make sure the info is correct.

Thanks for you help!!!

Tony

 

[audioholic 5,000+ posts]

Fuse size has nothing to do with length. The current capacity is always the same. Length only effects voltage drop.

Incorrect. Any wire sizing chart will confirm this, as one of its three criteria is the wire run length. The other two criteria of course are current flow and wire gauge.

You are 100% correct however that its a bad idea to put both a 60amp and a 40amp fure inline. This does not create a 100amp pretection, the 40 amp will still blow at 40amps, effectively rendering the 60amp fuse irellevant.

 

[n2audio 5,000+ posts]

18" vs. 18' doesn't make a difference?
thats new to me...

Sure it does...18' has about 10X the resistance (and V drop).

wanna sell that 200.2 //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Already did. Some friend of my brothers bought it for $120, and I didn't have to mess with shipping it.

My bro says the guy stuck it in some ghetto set up. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[audioholic 5,000+ posts]

18" also handles alot more current than does 18'. Again, any wire sizing chart will confirm this if you don't believe us.

 

[bonesninja 5,000+ posts]

Guys,
Lets say, if I do upgrade the power wire to 1/0, do I have to upgrade the ground at the battery? Right now, I just left it at stock.

If I do need to upgrade the ground, whats the process? Connect a cable to the - (negative) of the battery terminal and connect to a surface (metal) of the car.

So the negative terminal will have the stock ground and my new ground wire too? Just want to make sure the info is correct.

Thanks for you help!!!

Tony

your ground wire doesn't have to be ran back to the battery--its your choice--but most ppl just clean the paint off a spot in their trunk and bolt the ground right to the trunk floor as its already in the ground loop.

 

[KaeZoo 10+ year member]

18" also handles alot more current than does 18'. Again, any wire sizing chart will confirm this if you don't believe us.

All the wire size charts that relate current to length are designed to limit voltage drop. Voltage drop and ampacity are two different concepts. 18" can SAFELY handle the same amount of current as 18', but the longer run will create a larger voltage drop. If you have a 4 guage wire, its maximum safe current capacity is about 120 amps, regardless of length. However, if you have a longer wire run, you'll want a larger wire to limit the voltage drop.

When picking a fuse for a given wire gauge, the length of the wire doesn't matter.