how to: 2 270 H.O. alts on 1 battery bank ?

[kmak160]

I'm in the planing stage of a build and this is the first time i've messed around with the idea of running dual alts so im trying to gain some knowledge. The basic amp draws are as follows 300 for the mono, 50 for the 4 channel and 60-90 for the vehicle itself. Now that being said i want an over kill electrical system i will have a 410-440 amp draw and i want to meet/surpass this so i have zero drop in volts and room for future upgrades. So the question is if/how can i run 2 270 amp dc alts to one battery bank in thethe back and one batt under the hood. If this is not the best way to achieve my goals i am open to all advice. Thanx ahead of time Kyle.

[HHR Ed]

I think you may be going about it in a manner that is not the best. But, all batts and alts get connected in parallel.

I always suggest to setup electrical like this.

Figure the power you want to run.

You mentioned 350A draw for stereo. This will get you about 2800w of actual power when taking efficiency into account.

So, to make 2800w and a draw of 350A, you need batteries capable of sustaining that power for a fair amount of time.

Lets look under the hood first. A general figure is that the car/engine takes about 1000w of power. So now we need to power 3800w, or 450A.

Not sure what kind of car you have, I can always go to my site and do a yr/make/model search to see what fits. But for this example lets use an XS Power D3400. Output power is 4000w total.

That should be significant for your power range. However, these numbers are based off about 15 minutes capacity. So we can extend this with a supplemental battery. Nothing too serious.

Lets add an XP950 for a total of 4950w.

Now lets figure that alts needed to charge these batts.

D3400 is a 65 aH batt.

XP950 is a 35aH batt.

Total of 100 aH.

This number helps us figure the charge rate.

there is a 20% loss in efficiency with alts and batts so to get the 1:1 ratio we would need 120A of alternator charge. This gives us a good setup and will allow us to play long periods of time with the alt still charging the batts as we play. And if we play with the car off and kill the batts. It will take 1 hour to charge them back to full.

We can shorten this charge time if we wish.

You mentioned a 270A alt.

This will charge the total dead batts in about 26 minutes. And every minute of full power play will take 26 seconds to charge back up. This ratio is 1:0.44 which is 1 minute of play to 0.44 minutes of charge.

This is much more than adequate and even less charge will keep your batts topped off while playing music.

Most people dont play constant tones at 100% power for longer than 30 seconds so with music, you will be more than topped off.

Point is, you dont design your alternator setup to fully power your amps. It can't always be done, and it's unfiltered power at a slope (not consistent)

So you design you batts to power the amps, and design the alts to keep the batts charged.

Go ahead with your dual alt setup. Its an awful lot of money, time, and headache with getting it to run reliably and efficiently. And worth it only if you plan on running 12,000w or more

[kmak160]

Thanx for the post i was starting to think no one was gonna help lol. I see from what you said that i was going about it wrong. My idea was to add up the fuse rating of the amps then add in the draw of the suv.....05' suburban sry i should have stated that in my post. What im looking at are the new zv.4 subs that jacob from sundown is building in his section of smd. They are rated @ 1750 watts. My only goal is to have my electrical to the point that i can wang thsese daily and have no drop in voltage. Taking efficency into consideration will the saz-3500d be enough to push the subs to the max......for daily keep in mind. If i get this accomplished with only onle alt that would be awsome if could run one big alt say a dc 300 amp or more and meet/exceed my need to have an over kill electrical i would be ecstatic lol. I can see myself going to 4 subs and amps strapped in the future b/c nuthings ever good enough lol. Once again thank you for the knowledge its very greatly appreciated.

[bassface]

You would need to run 1 alts power to the front battery and the second alts power to the last in line rear battery, so you dont get both alts fighting each other.

[ALPINE408]

You would need to run 1 alts power to the front battery and the second alts power to the last in line rear battery, so you dont get both alts fighting each other.

lol

can't tell if your serious or not??????????????

also never new alts can fight each other ........... i got 20 on that one winning

so if thats true how do people with quad alts run them also how do people with 20 alts like alma gates run there alts without them "fighting" each other

thats a good one

[bassface]

You would need to run 1 alts power to the front battery and the second alts power to the last in line rear battery, so you dont get both alts fighting each other.

lol

can't tell if your serious or not??????????????

also never new alts can fight each other ........... i got 20 on that one winning

so if thats true how do people with quad alts run them also how do people with 20 alts like alma gates run there alts without them "fighting" each other

thats a good one

Thats what i was told when I bought my dual alt setup. I was told never put power on top of power, because the alt with a higher charging voltage will carry the load, I mean would you like to tell us the correct way or just be sarcastic?

[Bigsix]

^^ LMAO. I'd get started, but ive already chewed up n spit out my quota of 'tarded today

[Bump4life]

You would need to run 1 alts power to the front battery and the second alts power to the last in line rear battery, so you dont get both alts fighting each other.

lol

can't tell if your serious or not??????????????

also never new alts can fight each other ........... i got 20 on that one winning

so if thats true how do people with quad alts run them also how do people with 20 alts like alma gates run there alts without them "fighting" each other

thats a good one

Thats what i was told when I bought my dual alt setup. I was told never put power on top of power, because the alt with a higher charging voltage will carry the load, I mean would you like to tell us the correct way or just be sarcastic?

you realize if your front bat is connected to the rear bat bank it is still one system regardless of where your alts are connected. your front alt stil helps charge your rear bat bank and other alt still charges front battery. Your voltage problem lies with not having similiar voltage control modules or being set to same voltage.

[bassface]

Of course i realize that, but the charge is at least going through other batterys before meeting up. So how would you do it? Just connect both together on front battery?

[ALPINE408]

dual alts ran str8 to the batt bank everything is parallel so everything is gonna share and see the same load and all the same circuit