Calculator for amperage requirements?

[JakeW]

So per the video- I have 160ah. Multiply by voltage, to get watt hours. 14.2v is 2272wh, 12.5v is 2000wh. Efficiency at 70 percent, 14.2 provides 1590w &12.5 provides 1400w. I would be looking for 1500w x2, so 3000w divided by 70% effiency equals 4285w. I divided that by 13v average, and that gives me 329amps needed. 169 additional required. So I think a 280a alternator is required, to push this system 

[Dafaseles]

So 6000 watts... I'm not even going to do the math... get yourself the biggest ho alternator you can. 

Ok, I am going to do the math...

Lowest probable scenario, those amps are 70% efficient. They're probably a little better than that though. 6000÷70%=(about) 8,571. So let's say those amps need 8,571 amps of current to produce 6000 watts. 

Then divide 8,571 by 13 which is the average resting voltage of a depo cycle battery. 8,571÷13=(about) 659. So now we're at 659 amps of power. 

160 amp alt... assuming the car needs 40%. 160-40%=96 amps left. So we can subtract 96 from 659. 659-96=563. 

So now let's say your going to use those 2 batteries. 563-160(I still am a little sceptical about that Duralast being 80ah, but we'll use it) =403. So in this case, your short 403 amps of power. 

Not this math is not 100% perfect. Those amplifiers are probably better than 70% efficient, and usually, whatever amplifier you would use would never see total rms @1 ohm, but those Taramps Smart 3's get 3000 watts at 1 and 2 ohm, and do pretty well still down in the 4 ohm area. 

If I where you, I'd get the biggest alternator you can, and a third battery, or go lithium. 

[JakeW]

4 minutes ago, Dafaseles said:

So 6000 watts... I'm not even going to do the math... get yourself the biggest ho alternator you can. 

Ok, I am going to do the math...

Lowest probable scenario, those amps are 70% efficient. They're probably a little better than that though. 6000÷70%=(about) 8,571. So let's say those amps need 8,571 amps of current to produce 6000 watts. 

Then divide 8,571 by 13 which is the average resting voltage of a depo cycle battery. 8,571÷13=(about) 659. So now we're at 659 amps of power. 

160 amp alt... assuming the car needs 40%. 160-40%=96 amps left. So we can subtract 96 from 659. 659-96=563. 

So now let's say your going to use those 2 batteries. 563-160(I still am a little sceptical about that Duralast being 80ah, but we'll use it) =403. So in this case, your short 403 amps of power. 

Not this math is not 100% perfect. Those amplifiers are probably better than 70% efficient, and usually, whatever amplifier you would use would never see total rms @1 ohm, but those Taramps Smart 3's get 3000 watts at 1 and 2 ohm, and do pretty well still down in the 4 ohm area. 

If I where you, I'd get the biggest alternator you can, and a third battery, or go lithium. 

Lithium up front? Or in the rear? Does power you’re using, 1500w vs the amp being 3000 make any difference?

[JakeW]

I’ve got a guy near me selling an XS D3100 125ah for like $250

[Dafaseles]

9 minutes ago, JakeW said:

I’ve got a guy near me selling an XS D3100 125ah for like $250

how old is it? every experience is different, but my experience has been your average AGM lasts about 5 years before it starts losing charging and holding capabilities. That being said, that is a damn good battery

12 minutes ago, JakeW said:

Lithium up front? Or in the rear? Does power you’re using, 1500w vs the amp being 3000 make any difference?

Lithium by itself and never under the hood. People mix agm and lithium, but it's not recommended by the lithium companies unless it has Lifepo4 technology, even then they recommend using an isolator. 

You can't necessarily adjust the wattage output of an amp. I'm assuming you're talking about the gain. The gain is used to match the output voltage of the head unit, not set wattage output. It maybe not a bad idea to just run 1 Smart 3.

 

[JakeW]

26 minutes ago, Dafaseles said:

how old is it? every experience is different, but my experience has been your average AGM lasts about 5 years before it starts losing charging and holding capabilities. That being said, that is a damn good battery

Lithium by itself and never under the hood. People mix agm and lithium, but it's not recommended by the lithium companies unless it has Lifepo4 technology, even then they recommend using an isolator. 

You can't necessarily adjust the wattage output of an amp. I'm assuming you're talking about the gain. The gain is used to match the output voltage of the head unit, not set wattage output. It maybe not a bad idea to just run 1 Smart 3.

 

3 months old only, and they would both be agm, so that’d give me extra 127ah plus a ho alt. But now the space restriction. 2016 ram 1500 crew cab!

[JakeW]

And I mean yes they’re 3000w amps but im

only using 1500w

[Dafaseles]

8 minutes ago, JakeW said:

And I mean yes they’re 3000w amps but im

only using 1500w

How are you only using 1500 watts? 

 

11 minutes ago, JakeW said:

3 months old only, and they would both be agm, so that’d give me extra 127ah plus a ho alt. But now the space restriction. 2016 ram 1500 crew cab!

That's why lithium is nice. 1 battery will power the truck and the system. That's why I'm switching over to lithium

[JakeW]

Maybe I’m just getting wrapped up in the rms power, and not factoring the total power needed respectively.  Ooffff what’s a lithium of this size cost? 2 grand?

[Dafaseles]

8 minutes ago, JakeW said:

Maybe I’m just getting wrapped up in the rms power, and not factoring the total power needed respectively.  Ooffff what’s a lithium of this size cost? 2 grand?

The lithium I bought, depending on the alternator size, it's good from 10,000 to 14,000 watts. Cost me $1,057