How big of an alternator would i need for aproxiamentaly 4k?

[jaelliott9]

I have a Kicker zx2500.1 and a Kicker 650.4, have a stock and xs power d3400 under the hood.

[hdorre]

with my 230A, i hold low 13s..... at idle

thats with 3500wrms (at 12.x) to the subs.. and like 600ish wrms to mids and highs

Oh, those were with 2 diff setups (amps and box) too

[jaelliott9]

ok cool. i have been thinking about getting one of them js Ultimate alts 300amp, does anyone know anything about them

[OrzechNJ]

with my 230A, i hold low 13s..... at idle

thats with 3500wrms (at 12.x) to the subs.. and like 600ish wrms to mids and highs

Oh, those were with 2 diff setups (amps and box) too

how many batts do u have ?

[hdorre]

with my 230A, i hold low 13s..... at idle

thats with 3500wrms (at 12.x) to the subs.. and like 600ish wrms to mids and highs

Oh, those were with 2 diff setups (amps and box) too

how many batts do u have ?

(2) G24s.. but i dont really even drop into rest.

[jaelliott9]

thats awesome.

[rockFord_Expedition]

4k?

So lets say your 2500 is a good 75% efficient due to it being class D

2500(Watts out)/.75(Efficiency) = 3334 Watts in needed

650.4 is a class AB so it can run at about 60% efficient iirc

650/.6 = 1084 Watts in needed

3334 + 1084 = 4418 Watts needed to your amps.

If your Alt will charge at 14V we take 4418/14 = 316 Amps needed at 100% duty cycle. No music really runs at that, so lets call it a 50% average duty cycle, 316*.5 = 158 Amps @ 14V to keep your amps playing to their full potential on music.

You still need to account for things like the amperage your vehicle and other electrical components will need, voltage drop accross your wire, and the amperage your batteries need to maintain a surface charge.

[rockFord_Expedition]

ok cool. i have been thinking about getting one of them js Ultimate alts 300amp, does anyone know anything about them

Never heard of them.

I have heard good things about Mechman, DC Power, Singer, and can vouch for DC Power personally.

[Miguels]

that kicker amp is beast. i wouldn't be surprised if its pushing over 3k watts

230a should be about the border line a 270 will be optimal. another thing is to move one of the batteries to the rear so the power wires are shortest and have less resistance

its not the same pulling 250 amps from a 17 foot long power wire to pulling 250 amps through 4 feet of power wire

[rockFord_Expedition]

that kicker amp is beast. i wouldn't be surprised if its pushing over 3k watts

230a should be about the border line a 270 will be optimal. another thing is to move one of the batteries to the rear so the power wires are shortest and have less resistance

its not the same pulling 250 amps from a 17 foot long power wire to pulling 250 amps through 4 feet of power wire

Your last sentence is correct but he wont be pulling 250 Amps from any battery. Voltage will be pulled from the source with the highest voltage even if it isn't the closest. Battery resting at 12.x and Alternator charging at >12.x means it will draw current from the alternator.

Not saying that moving the battery is a bad idea, or that shorter runs of wire aren't beneficial.

OP, if you are getting an alternator that will provide the juice you need, and won't play the system without the engine running, in that case, an extra battery will only benefit you by providing more juice to start your car with. Other than that, it will draw amperage from your alternator to maintain its surface charge while the vehicle is running and your system is playing. I will say it again before someone chimes in about this, I am only talking about the 2nd battery being a burden IF you get an alternator that can supply the voltage and current that your vehicle and aftermarket electrical need.