What is the correct way to wire non-matching dual alternators??

[rival904 10+ year member]

I only have my ford alt in right now as I am still waiting on the rest of the stuff for my alt bracket from DC power.

The toggle switch is just to switch voltages, 14.8 to 15.3 and I dont have that, just the simple install it and forget it.

I sit at 14.8 with 1 alt in there, and when I add the other I should be at 15.3

No problems, took 30 days from when I ordered till it was at my door, my truck used to sit around 14.0-13.8 and its bounce back and forth, now its alot more steady.

 

[rival904 10+ year member]

Hmmm... now you have me thinking.So a 275amp alternator should be sufficient to run a 7000watt RMS system? I was assuming the saz-3500d amp would consume maybe 200amps of current at full tilt... possibly more at 14.4v. I do plan on running 3-4 D3100 XS power batteries though. I'd just hate to finish the build and get voltage drops if you know what i mean... so i tend to try to overkill the charging setup "just incase." I guess you can say more power is better then not enough.

Your not understanding how this works.

Your alt does 275 amps at full tilt, NOT at idle.

IDLE output is more important.

Higher voltage = less amperage to produce the same power.

 

[Villeza1 10+ year member]

Hmmm... now you have me thinking.So a 275amp alternator should be sufficient to run a 7000watt RMS system? I was assuming the saz-3500d amp would consume maybe 200amps of current at full tilt... possibly more at 14.4v. I do plan on running 3-4 D3100 XS power batteries though. I'd just hate to finish the build and get voltage drops if you know what i mean... so i tend to try to overkill the charging setup "just incase." I guess you can say more power is better then not enough.

Lol Sure. I'm running 1 250a H/O alt on ride and system. System (when finished) will be doing around 13,000 wrms @ 1ohm with a battery bank of 5 XS Power D3100's...You'll do just fine Lol

In todays car audio (assuming daily setup), there is no real way to match charging input to amp draw. So it's best not to play at full tilt all day everyday. You gotta give your batts a chance to charge or get an external charger and charge your batts up at night.

 

[Villeza1 10+ year member]

Your not understanding how this works.
Your alt does 275 amps at full tilt, NOT at idle.

IDLE output is more important.

Higher voltage = less amperage to produce the same power.

^^This^^ plus alt will reach near full potention at around 2k-2.5k rpms.

 

[rival904 10+ year member]

Yup, both my alts do 160-180 at idle and around 270 each at full tilt @ 15.3v

Planning on running ~12k rms across 9 batts

 

[Villeza1 10+ year member]

Yup, both my alts do 160-180 at idle and around 270 each at full tilt @ 15.3v
Planning on running ~12k rms across 9 batts

Jeez 9 batts? You must be planning to bang for a long time?

What batts are you running?

 

[rival904 10+ year member]

Optima D31's

Ive always followed the rule, 1 batt per 1kw rms.

 

[94Mazda626 10+ year member]

^^This^^ plus alt will reach near full potention at around 2k-2.5k rpms.

Yup, and output will fall off somewhat after being run for a while and the alts get hot.

 

[Villeza1 10+ year member]

Optima D31's
Ive always followed the rule, 1 batt per 1kw rms.

You know if you run deka intimidator 9a31 or XS Power D3100 you would only need 4, 5 to be safe,right?

EDIT: Also less weight with the Deka's or XS Power.

 

[kpeters0929 10+ year member]

I totally understand how the amperage works on the alternators. At idle the large case GM alternator puts out roughly 180 amps at idle. I just never thought that it would be able to be enough by itself for the new setup.

Previously i had (2) 13w7 subs with (2) 1000/1v2's. I also had (1) kinetik HC1400 under the hood and (2) HC1800's in the back. With my current 200 amp H.O. alternator my voltage would still drop as low as the 11's even if i were driving 30+mph. This would be at full tilt though, and it would drop that low if i were to play say longer then 20 sec. Now that i was changing the setup i figured it would be mandatory to add another alternator to support more power... and their really isn't a way to put a bigger alternator in the stock location on the car (intake manifold is in the way.) So if it should have handled the power idk why it was dropping that low to begin with. All the wiring was 1/0 gauge. Everything was done right. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[Villeza1 10+ year member]

I totally understand how the amperage works on the alternators. At idle the large case GM alternator puts out roughly 180 amps at idle. I just never thought that it would be able to be enough by itself for the new setup.Previously i had (2) 13w7 subs with (2) 1000/1v2's. I also had (1) kinetik HC1400 under the hood and (2) HC1800's in the back. With my current 200 amp H.O. alternator my voltage would still drop as low as the 11's even if i were driving 30+mph. This would be at full tilt though, and it would drop that low if i were to play say longer then 20 sec. Now that i was changing the setup i figured it would be mandatory to add another alternator to support more power... and their really isn't a way to put a bigger alternator in the stock location on the car (intake manifold is in the way.) So if it should have handled the power idk why it was dropping that low to begin with. All the wiring was 1/0 gauge. Everything was done right. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

That doesnt sound right, 2k with that kind of batter bank shouldn't drop no lower than 14v. I had a 250a H/O alt with 4 HC1800's 1 under then hood and 3 in the back with 2 crunch gp3000d pro's strapped at 2 ohm with roughly 6k rms and my volts didnt drop any lower than 12.7v.

I'm guessing your alt is damaged or it's a user error.

EDIT: Did you do the Big 3? Did you have good grounds?

 

[rival904 10+ year member]

You know if you run deka intimidator 9a31 or XS Power D3100 you would only need 4, 5 to be safe,right?
EDIT: Also less weight with the Deka's or XS Power.

And whys that?

Any technical data to back that claim or just brand favoritism at its best?

 

[kpeters0929 10+ year member]

That doesnt sound right, 2k with that kind of batter bank shouldn't drop no lower than 14v. I had a 250a H/O alt with 4 HC1800's 1 under then hood and 3 in the back with 2 crunch gp3000d pro's strapped at 2 ohm with roughly 6k rms and my volts didnt drop any lower than 12.7v.
I'm guessing your alt is damaged or it's a user error.

EDIT: Did you do the Big 3? Did you have good grounds?

Yes you name it and i tried it. Like i said 1/0 everywhere. Real clean install. Checked all the ground resistances etc. I even ran a 1/0 ground wire from the underhood battery to the rear batteries. What i do know is that the small case GM alternator sucks according to all the builders. Actually after i think about it, i think it is a 160 amp.... not 200. It's still a high output considering stock it was a 90amp, but i guess in the small case GM's it doesn't have enough room inside to build it any stronger. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[Villeza1 10+ year member]

And whys that?
Any technical data to back that claim or just brand favoritism at its best?

http://www.stevemeadedesigns.com/board/index.php?showtopic=58124

Here's a hint of proof plus go to the website and review the batt yourself. Bump it against the optima yellow top.

btw, I dont nut hug to specific brands, I nut hug to performance. FYI

 

[Villeza1 10+ year member]

Yes you name it and i tried it. Like i said 1/0 everywhere. Real clean install. Checked all the ground resistances etc. I even ran a 1/0 ground wire from the underhood battery to the rear batteries. What i do know is that the small case GM alternator sucks according to all the builders. Actually after i think about it, i think it is a 160 amp.... not 200. It's still a high output considering stock it was a 90amp, but i guess in the small case GM's it doesn't have enough room inside to build it any stronger. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

If it was a shitty built alt then you can expect shitty performance. If you have a more powerful, well built, durable, reliable alt then I think you will see a better voltage in your systems performance.