4k rms what do i need?

[newls1]

Why are they both multiplying the reserve capacity of the battery :S

spill the beans boon!

[Guest]

Why are they both multiplying the reserve capacity of the battery :S

dont ask me i wasnt fact checking any of it.

[P4killer_]

lol idk saw it in one of those tuts i saw... lol

like i said, correct me if im wrong, lol but um yea i used 80% efficency, 70 would be safer, idk what amp etc, but i thought its more like a rough guideline kinda thing....

and tht vid said to factor 40% of your alts power going to your car, therefore leaving 60% for bass and misc

so im thinking if your car has a 105amp stock alt, 40% of 105 is 42amps leaving 63 left for use. now if you upgrade your alt to a 300 amp alt, your car car isnt going to suddenly use more electricty just because you bought a bigger alt. it should still ROUGHLY be that same 42 amps which would leave you with 258 amps left to use and lets just say at 13v because 14 is assuming almost no voltage drop. so 258*13= 3354watts to use..

and OP wants 4k rms and if that amp were 80% efficient, it would require 5000watts * 80% efficiency to make that 4k..

ill see if i can find that mike styers vid

by all means though, show me the error in my ways never hurts to learn

[P4killer_]

http://www.stevemeadedesigns.com/board/ind...showtopic=55040

i watched it real quick:

yea using that tut at 80% efficiency and the scernario above a 300 amp alt + a k2400 is spot on pretty much to meet the 5000w required...

yea idk much about batteries really how to tell if its good or not ie:. why a battery with less ah might be better than a similar battery with more ah..

Edited October 20, 2009 by P4killer_

[dirtboi22]

http://www.stevemeadedesigns.com/board/ind...showtopic=55040

i watched it real quick:

yea using that tut at 80% efficiency and the scernario above a 300 amp alt + a k2400 is spot on pretty much to meet the 5000w required...

yea idk much about batteries really how to tell if its good or not ie:. why a battery with less ah might be better than a similar battery with more ah..

thanks is not enough man! i understand all of it now!!!! i appreciate it big time!

[P4killer_]

loll like i said those are like guidelines, and obviously some people think im a lil off on what i came up with but from what i can tell it should be right, it would be nice if they would chime in and enlighten me but yea i mean the above should be good

[P4killer_]

idk why it keeps double posting...?

Edited October 20, 2009 by P4killer_

[MECHMAN]

There are a few things to comment on in this discussion.

1) A battery does not supply or create current, it is only a reservoir for current, a means of storage, and should not be figured into anything when determining alternator needs.

2) A true 300 amp alternator for most vehicles, is not going to have good output at idle. (unless it were absolutely huge)

3) Most vehicle's alternator belts are not capable of turning a true 300 amp alternator without a fair amount of belt slip

4) Most vehicles use around 40 amps for basic accessories. (some are more, some are less)

5) A 300 amp alternator is going to make substantially less than 300 amps when at full operating temperature, and substantially less than that at idle.

6) Hardly anyone has more alternator amperage than their amplifier/vehicle can use at full volume, yet systems still work fine. (that's why the batteries are important)

All you can do is find the alternator with the best overall output curve for your type of vehicle, and run high quality batteries. I wouldreccomend at least 100lbs worth of high quality AGM batteries coupled with a minimum of a 200 amp alternator. Your listening habbits, music choice, box design, as well as many other factors will determine how long you can listen at full volume, and what kind of voltage drops you will experience.

[P4killer_]

not to thread jack OP but while we are the subject, i was getting my ideas and numbers from that tut which seem to be ideal or overkill

so i mean i see extreme builds with like 32+ batteries and i also see comparable builds power wise with a fourth of that, kinda confusing

obvi the higher the voltage you can keep equals the better

so the OP wants minimal batteries and to do that, you would need a beefy alt otherwise your looking at several batteries, now im confuzzled i wish there was a sticky about this... obvi my electrical knowlege is a bit under par?

[wL<3bass]

Hardly anyone has more alternator amperage than their amplifier/vehicle can use at full volume, yet systems still work fine. (that's why the batteries are important)

If you into song with long low basslines I would recommend a DC Power 270XP 270amps (200idle) with a hc1400 underhood (or equivalent) and a 1-2 hc2400 (or equivalent) in the rear.

Depending on your cars amperage needs and amplifier efficiency will dictate whether you need 1 or 2 hc2400 in the rear.

Edited October 20, 2009 by wL<3bass