Running power wire direct off alt?

[jolly_26 10+ year member]

Is it all good to run my power wire off of my alternator? My car is mid engined, and the battery is in the front, and the amps will be going in the rear trunk, and it would be much easier to run my 0 gauge through only one firewall. Is this a good idea or will I get alt whine etc? I figure since my battery positive is of course connected to my alt positive it shouldn't make too much difference?

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[winkychevelle 10+ year member]

it wont hurt but u might notice a little more dimming due to the battery not being able to buffer the current peaks as well depends on how much power you are running i guess though i doubt it will make much of a difference at all

 

[jolly_26 10+ year member]

it wont hurt but u might notice a little more dimming due to the battery not being able to buffer the current peaks as well depends on how much power you are running i guess though i doubt it will make much of a difference at all

Cheers man, eventually I will run some bigger cable up to the front batt anyway. Time to go wire these in then, so hard in the cold it's like -5 outside. On another note, I'm pretty sure you comment on every one of my threads hahaha

 

[wErd 5,000+ posts]

Cheers man, eventually I will run some bigger cable up to the front batt anyway. Time to go wire these in then, so hard in the cold it's like -5 outside. On another note, I'm pretty sure you comment on every one of my threads hahaha

-5? Lulz. It was 109* F here today

 

[goingdef 10+ year member]

I would not even think about doing that, you need to run the amp's power wire all the way to the battery or run a battery in the trunk but your alt is going to kick out under the amp load and you will then be relying on whatever power wire is running from the alt to the battery which is not going to be fused for that load and it's going to blow leaving you with no charging system! Just do it right or you will experience some serious problems!

 

[rebelfromva 10+ year member]

alt to batt in rear to amps?

 

[wenn_du_weinst 10+ year member]

um do not do that, if you know how an alternator works you will understand why. It WILL damage your alt.

 

[goingdef 10+ year member]

alt to batt in rear to amps?

safest way to do it! at least in his situation.

 

[quackhead 10+ year member]

Is it all good to run my power wire off of my alternator? My car is mid engined, and the battery is in the front, and the amps will be going in the rear trunk, and it would be much easier to run my 0 gauge through only one firewall. Is this a good idea or will I get alt whine etc? I figure since my battery positive is of course connected to my alt positive it shouldn't make too much difference?

You have got to have a energy storage device :Battery. For your system, the battery should be a deep cycle with adequate Ah/CCA's, depending on the amp(s) you use..Could you mount a good AGM by the amp location and reroute the factory power wire to it? This would still maintain one wire hole through the firewall (just bigger for the big 3 wiring)

 

[ThatChevyGuy 5,000+ posts]

I have it ran right off the alt,(actually the hot wire going to it, it had a spot for a second wire) i had to install a second battery because the truck would SHUT OFF.

 

[Kangaroux 5,000+ posts]

Yeah running right off the alt is not a good idea. Consider this: when your voltage drops, your battery starts to take over some of the current draw from your amps (hence why your voltage stays in the high 12's). If you remove batteries from the picture, the alternator voltage will continue to drop to the point where your vehicle electronics cannot function.

 

[jolly_26 10+ year member]

Yeah running right off the alt is not a good idea. Consider this: when your voltage drops, your battery starts to take over some of the current draw from your amps (hence why your voltage stays in the high 12's). If you remove batteries from the picture, the alternator voltage will continue to drop to the point where your vehicle electronics cannot function.

Ok sweet as, will have to re think things, may even do amps in the front, it would help with weight balance to have a little more up there. I think fully loaded the car has a 58% rear weight balance anyway.

But as for your comment, surely the batt still plays a part? It is just a little further away along the cable? In total the system will be only around 700 watts anyway.

 

[maylar 10+ year member]

Guys, guys....

The alt and battery are connected. It's the same point electrically. The alt supplies power when the engine is running, not the battery. It's totally OK to run the amp power off the alternator terminal. I have an install like that for 10 years without issues. Of course the "big 3" becomes even more important if you run the system without the engine running. Need to make sure the batt to alt wire is fat enough.

 

[xSPLoder 10+ year member]

It will prolly cut that alts life to next to nothing from the constant current loads plus it will rob your vehicles required power needed to function properly. If its only temp, you might as well wait till your ready to do a full run from battery back. Don't forget too that if the amp isn't getting the proper constant power needed, you could fry that as well

Of course all of this is IMO

 

[jolly_26 10+ year member]

A lot of different opinions/theories on this and I'm still pretty lost, although @maylar is thinking exactly the same way as me now that I look at it more. It is not as if the battery will be excluded, it will just be a bit far away, and the positive and ground wire will have to be stepped up quite a bit.