Need Help With Power Supply

[RF4LIFE]

I have a 2004 Ford Explorer and I putting a large system in it. I have the stock 130Amp Alt. and the stock batt. I have two amps and combined they are at least 2400w RMS and will possably be as high 4100w RMS. I did the Big 3 upgrade and I'm wondering if I will need a bigger Alt. and if so how big should I get? Also how many extra batterys should I get and what size amp or amphour should they be? Size Isant unlimited so the smaller the better so if I can use one larger vs two smaller than let me know. Thanks

[TRON]

I'm no professional but I understand electricity enough to tell you that you definitely need a HO alt/battery

The total wattage that your vehicle can produce is found by multiplying the amps by the voltage. 140amps x 14.2 (typical charge) = 1988 watts available.

Consider that your vehicle uses some of that power...lets say 60 amps? (60x14.2= 852watts) that leaves you with 1136 watts left over for any aftermarket electronics.

Also consider that NO amplifier is %100 efficient... maybe %80 and that's really good. If you want to run a total of 4100watts ( 4100/14.2=288amps) You need a minimum of 288 amps surplus.

Check out Mechman or Singer alternators, you'll probably want something big like 350 amps or dual alts.

And make sure you get a battery or two because the battery acts like a filter to smooth out the current created from the alt as is converts AC to DC

So see what XS power has for your application.

!Send emails to these people, they'll hook you up with the right stuff!

*remember* - Wattage is the transfer of electricity...not "power" or whatever. Your amplifiers say they can make 4100 watts ONLY if that amount is available. If you don't have enough current to feed your amplifiers they will try to draw more power, resulting in a voltage drop which will cause excessive heating and probably do bad things to you battery or alt.

- fixed my horrible spelling -

Edited April 25, 2012 by TRON

[RF4LIFE]

So I should be looking at my Amps RMS or Peak Watts when trying to dice an Alt.?

4100w RMS / 14.2v = 288.7A

288.7A + 60A (for the electrical systems) = 348.7A

8200w Peak / 14.2v= 577.5A

577.5A + 60A (for the electrical systems) = 637.5A

So should I look for a 350A Alt. or like two 325A Alt's?

And what size batteries should I get for the back?

[Trey_Dog650]

Always look at rms. and I think you'd be fine with a 350 amp alt plus an upgraded stock battery and 2 more in the back for a total of three.

[RF4LIFE]

How big should they be? CA? CCA? Do Thoes matter?

[Zapanater]

That refers to the cranking amps, which is a useful measurement when you need a large discharge over a short time, such as cranking over an engine, but not terribly useful for the continous drain of a high power system. Generally speaking though, the more cranking maps, the better the battery. Otherwise, look at the "ah" rating. THis is ampere hours, and let's you know how much reserve it has. A good battery like an xs power d3100 has 110ah. It doesn't even tell you the cca or ca on their site. Id think one of these would eb enough, or two conventional lead acid batteries, provided you have an upgraded alternator. Check out maniac motors for an HO alternator if you're on a budget.

[RF4LIFE]

Well should I just get like two Yellow Top batteries? As big as I can fit?

[CrownVic]

just get the biggest sealed batts you can fit/afford if you plan on playing the system much with the car off.

[TRON]

Well if you're talking about over 8000 watts peaking then you'll definitely want to run dual 300+ alts and two or three batteries. Id say for batteries... XS Power's D3100 or XP3000. These batteries have the best Ah (amp hours) and maximum amp ratings. Terribly pricy but that's the cost of big power. I'm betting that you can get two 350 amp alts and the necessary hardware from Mechman. You'd have to find out if you can run two alts under your hood becasue typically, when you have multiple alternators, you leave the stock one in and just add extras, then you know that your aftermarket alts are only supplying power to your amplifiers.

[skittlesRgood]

So I should be looking at my Amps RMS or Peak Watts when trying to dice an Alt.?

4100w RMS / 14.2v = 288.7A

288.7A + 60A (for the electrical systems) = 348.7A

8200w Peak / 14.2v= 577.5A

577.5A + 60A (for the electrical systems) = 637.5A

So should I look for a 350A Alt. or like two 325A Alt's?

And what size batteries should I get for the back?

be worried. the info in this thread sucks so far.

your math is off because you didnt factor efficiency. you need more like 470amps. dont ever ever ever ever ever ever ever, ever look at peak or max power ratings. they are useless. rms only!!! so a 250amp alt with a higher idle output than a 300amper, with two xs power 2400s plus a starting battery and you will be covered.