The Big 3 Help

[cjosisek90 0]

Hey guys,

I recently got my 1/0 gauge wire in the mail the other day, I am prepping it up with the clamps and getting the right sizes, and I look on the website and I see that I need a fused wire. I looked at the big 3 post and it says I should get the factory sized fuse.

Can I get some pictures or some detailed information about the setup involved into this?

I looked into the Big 3 post and nothing is explained into detail.....Only what it is.

Any information would greatly help.

Thanks,

-Curt

[cjosisek90 0]

bumping is what we do best

[cLutcH 0]

The wire that needs to be fused is the one running from the alternator to the battery. And the fuse has to be matched to the output of the alternator. There is controversy about where the fuse should be. Some say in the middle, some say closer to the alternator, and some say towards the battery. I couldnt get a straight up answer anywhere so i just put it in the middle. Nothing blew yet

[cjosisek90 0]

The alternator I have now, is only 90 amps, is that what size of a fuse i should get? "90Amp fuse"

Source: Nippondenso

[johnecon2001 82]

Put it in the middle of the wire and fuse to the max amperage of the WIRE. Not the Alternator.

And don't bump your post 1 minute after you make it.

[cjosisek90 0]

So being a 1/0 Gauge wire, would 200amp fuse work?

I am looking at the wire and it only tells me the volts and degrees.

Thanks,

-Curt

[johnecon2001 82]

For that short of a distance? I would fuse at 350A.

[cjosisek90 0]

Ok, thanks John, Ill be hooking up the Big 3 sometime this spring break then.

Thanks,

-Curt

[cLutcH 0]

Put it in the middle of the wire and fuse to the max amperage of the WIRE. Not the Alternator.

And don't bump your post 1 minute after you make it.

This is another controversy. His alternator is a 90 amp. If he is running 1/0awg. He will never put enough current through that wire to match its maximum capacity. You fuse should match your alternator so in case the battery tells the alternator to put out more power than it can, it wont blow your alternator. Then you will be forced to get a H.O.

[NDMstang65 403]

250 amp fuse works fine...

Thanks!

-Nick

[johnecon2001 82]

Put it in the middle of the wire and fuse to the max amperage of the WIRE. Not the Alternator.

And don't bump your post 1 minute after you make it.

This is another controversy. His alternator is a 90 amp. If he is running 1/0awg. He will never put enough current through that wire to match its maximum capacity. You fuse should match your alternator so in case the battery tells the alternator to put out more power than it can, it wont blow your alternator. Then you will be forced to get a H.O.

Explain how the battery tells the alternator anything.

[cLutcH 0]

Put it in the middle of the wire and fuse to the max amperage of the WIRE. Not the Alternator.

And don't bump your post 1 minute after you make it.

This is another controversy. His alternator is a 90 amp. If he is running 1/0awg. He will never put enough current through that wire to match its maximum capacity. You fuse should match your alternator so in case the battery tells the alternator to put out more power than it can, it wont blow your alternator. Then you will be forced to get a H.O.

Explain how the battery tells the alternator anything.

At idle your stock alternator is only putting out about have its amps. That is because the battery doesnt have much strain and much of its power isnt being used. While driving with the radio, fan, lights, phone charger, ect, the battery is using much more current and that is where the alternator is putting out most of its power. If he is running 1k+ watts through his system alone, his battery is drawing a LOT more current from the alternator, and that is where electrical problems occur. Just like any motor, overworking causes problems.

[jack 0]

I am not qualified to agree,argue or otherwise. I just wanted to throw my impression out there for further clarification and I might learn something.

I thought that the Alty was a fixed part of the equation, what I thought was that the alty generates power based on the rpms which it is spinning, period. And that at 2200 rpms whether the lights and stereo are on or off, the same exact power is being generated and is pushed toward the battery, feeding the car on the way, and the battery just receives power as needed.

You said "While driving with the radio, fan, lights, phone charger, ect, the battery is using much more current and that is where the alternator is putting out most of its power." Don't those things get their power from the alty unless the alty is not providing any power? And the battery doesn't "use" current, does it? I mean the power from the alty is made available to the car before the battery can charge from it anyway, right? look at the order of the connections.

So is the alty generating more power at the same rpms or is it simply that more of it's generated power is being drawn?

To paraphrase, I thought that the altys output was a constant based on rpms and that the battery's purposes were to A -store power (you know, to start the car and more) and B -deliver power in the event that the alty is wither spinning slow not at all and C it is the last thing to receive power and it only draws power that is forced on it, after the car's needs are met, up to it's capacity as it.

Or have I been misinformed? The alty does vary it's own output based on a need that is senses and reacts to

So, when I thought that the battery assists the alty by storing and delivering power in the even that the alty is unable to or it's output is not enough I was wrong and it's actually visa versa, the battery delivers power and alty only "kicks in" to assist and re-charge the battery to deliver power as needed?

Any electrical engineers in the house who can explain. I just want to know if I have had a long term misconception or partially or not at all?

I also thought that when the lights dim it was because the alty's supply is not quite enough to power everything that is connected to it and the amp draws the most and takes more than it's fair share and so the lights have to deal with less power than they need partially because the battery can't unload its stored power fast enough. is that wrong also?

[lee 2]

Actually, the alternator only puts out what is required from it until it cant supply any more above its ability then the battery starts to discharge aswell. e.g. at idle if no other loads are presented to the alt and you clamp the output wire, i've seen well under 20 amps. This is due to the battery being the only difference of potential. Output at idle can be under 10 amps especially if the battery is over 75% charge or { 12.45v }.

[bmr4life 0]

You always fuse to the wire capacity. Anything else is pointless unless the individual componenets connected to said wire do not have their own fuses.

The fuse inbetween the alt and the battery is protecting the WIRE. Not the battery. Not the alt.

Edited March 26, 2008 by S197