Voltage experts!! Help!!!

[SethPhillips 5,000+ posts]

Regardless of how many runs. I feel I should not have to do all that. I am only running 3000 watts with a 250 amp alternator. I know people running more power with smaller alternators and having voltage fine.

is this at idle.. i know that HO alt's need to be ran at a higher RPM in order to see a higher voltage..

right now at idle you are probubly seeing more amprage output from the alt then voltage.

im sure once you rev ur engine up to a higher RPM you will see higher voltage.

 

[MECHMAN 10+ year member]

The Voltage reading of the alternator is a function of amperage. Any time your electrical load exceeds what the alternator is putting back in to the system, you will see a drop in voltage. The reason why many HO alts have low voltage at idle, is beause they do not put out very much amperage, and therefore expierience a votlage drop.

If you read in his first post, he only gains a couple tenths of a volt by revving the engine; it is not an RPM issue.

 

[mazzasec 5,000+ posts]

Ya I know its definetly NOT the alternator. When I was driving down the highway at full tilt I drop to about 12.1 (and im putting out 2000rpms while driving down the highway) but right as I turn it down its back up to 14.4 in like 45 seconds. So far as for wire upgrades this is what I have done.

1 UNFUSED run from the front battery to battery in the rear +

1 FUSED run from the front battery to the rear +

Grounded BOTH batteries in the rear to the chassis

Ran 2 WIRES from each - in both rear batteries

Ran 2 WIRES from each + in both rear batteries

1 unfused + run to the amp

Full tilt at 2000rpms voltage drops to 12.1

at idle 11.7-8

 

[orangecounty1 10+ year member]

imo, pretty much
best thing an HO alt is gonna do is increase the time needed between charges

when you have a bank of bateries you need to charge them back up from time to time....i need to do mine, maybe ill buy a charger tomorrow

if you put a full charge on the batteries, they will last you longer between charges than if you had a stock alt

so yes, i think that they are a waste.....unless you have enough amps coming from alts they will support your whole system and car, then it is worth it

i agree, never really thought of it that way, until u explained it to me the other day. im just gonna get a few good batts and i have a charger i can throw it on every week or whatever, even get one of those battery tenders.

 

[mazzasec 5,000+ posts]

I already took everything out and selling the DEKA's I am going back with kinetik and I will see how that does.

 

[njaykaplan 10+ year member]

The sundown does draw way more at half ohm than 1 ohm, I had ran mine on a pair of dual 2 memphis mojos for a while until i removed one so i could just run 1 ohm. I have a stock 150 amp alternator, a kinetik 2000, and a pair of orbital deep cycle batterys and i did not have much drop at all on 1 ohm.. at half ohm i'll drop to high 12s.. At 1 ohm it'll drop around .5-.8 volts from 14.. I just hooked up the sundown in a cobalt, so i'll see what kind of drops it has. I believe its a stock 130 amp alternator, but i'm not sure. The stock battery is in the trunk, and i replaced it with my 2 orbital batterys to test.

 

[iamamp3pimp 5,000+ posts]

let us know how it goes

maybe the dekas need a charge to top em off as well.

 

[njaykaplan 10+ year member]

Has anyone had similar problems out of a deka battery? Maybe it cant give 400 amps so easily, I just hooked up a system in a rental car and it sounding pretty badass right now and not a ton of voltage drop, but i'm just running the saz at 1 ohm. I have my kinetik in the garage, and just using the pair of orbital batterys.. Once i get out of my house, i'll bring my DMM and see how much i can make it drop, since its basically thrown together. Do you have access to any other batterys to swap and give it a try without throwing the money away?

 

[MECHMAN 10+ year member]

The orbital batteries will actually have a higher burst discharge rate than the kinetik will. The kinetiks are designed for extended use just like the Dekas do, they aren't the greatest SPL battery, that's why they are cheap.

If you can get Orbitals or red-tops cheap, then run those. Otherwise, Powermaster is your best bet.

P.S., are you running your 1/0 ground cables through the floor and to the passenger side frame-rail? The alternator, front battery, rear batteries and amp should all be grounded to the frame-rail itself if possible, not the sheet metal floor.

 

[IDSkoT 5,000+ posts]

The orbital batteries will actually have a higher burst discharge rate than the kinetik will. The kinetiks are designed for extended use just like the Dekas do, they aren't the greatest SPL battery, that's why they are cheap.
If you can get Orbitals or red-tops cheap, then run those. Otherwise, Powermaster is your best bet.

P.S., are you running your 1/0 ground cables through the floor and to the passenger side frame-rail? The alternator, front battery, rear batteries and amp should all be grounded to the frame-rail itself if possible, not the sheet metal floor.

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I don't have the man power to do that to my car.

I just grounded that bish to the strut!!!

Not really... I grounded it to an opening in my trunk.

It works well enough for my little setup.

 

[Skip01 5,000+ posts]

Hmmm....ill just throw this up for comparsion since we both have 2004 Explorers and about the same rated watts

300amp EA alt

2 Batcap2000s underhood

2 PowerMaster D3100s

1 NSB125

Amercian Bass 200.1 @ .5ohm

Only a single 4ga POS run from front batts to rear

Idle, amp on but not playin 14.2

Idle radio off 14.5

Full Tilt it goes too like 12.6 - 12.6, if im playin something very constant

Batts rest at 13v....havent charged them in a bit

What do yours rest at? They may need a good overnight charge

But man 12v is fine if thats the lowest youre dropping too.

 

[DidUHearThat? 10+ year member]

Hmmm....ill just throw this up for comparsion since we both have 2004 Explorers and about the same rated watts
300amp EA alt

2 Batcap2000s underhood

2 PowerMaster D3100s

1 NSB125

Amercian Bass 200.1 @ .5ohm

Only a single 4ga POS run from front batts to rear

Idle, amp on but not playin 14.2

Idle radio off 14.5

Full Tilt it goes too like 12.6 - 12.6, if im playin something very constant

Batts rest at 13v....havent charged them in a bit

What do yours rest at? They may need a good overnight charge

But man 12v is fine if thats the lowest youre dropping too.

Your running 3500+ watts off a 4 gauge? 2 volts of drop? You think that's okay? Your choking your amp with thin wire. Get some thicker wire and your performance will improve.

 

[Skip01 5,000+ posts]

Your running 3500+ watts off a 4 gauge? 2 volts of drop? You think that's okay? Your choking your amp with thin wire. Get some thicker wire and your performance will improve.

I ran that up to 156.1, right now its about 153ish

Doesnt matter, itd run off batt even if i had 10 runs of 1/0

 

[mazzasec 5,000+ posts]

Hmmm....ill just throw this up for comparsion since we both have 2004 Explorers and about the same rated watts
300amp EA alt

2 Batcap2000s underhood

2 PowerMaster D3100s

1 NSB125

Amercian Bass 200.1 @ .5ohm

Only a single 4ga POS run from front batts to rear

Idle, amp on but not playin 14.2

Idle radio off 14.5

Full Tilt it goes too like 12.6 - 12.6, if im playin something very constant

Batts rest at 13v....havent charged them in a bit

What do yours rest at? They may need a good overnight charge

But man 12v is fine if thats the lowest youre dropping too.

Ya but the thing is I feel I shouldnt be dropping that low. With 1 g34 2 g31s and a 250 amp alt. I am idling at 14.4. Hell it stays 14.4 until I REALLY crank the bass up. Then it just all goes to hell.

 

[BoomBoomBoy 10+ year member]

What is the voltage when you rev it steady to say, 3000rpm?