Dual Alternators

[RoadEyePie]

Ok, I'm almost electrically illiterate. So my GMC Denali 3500 HD diesel dually has dual alternators. Can some one explain how they work? I Googled, I read, and I didn't understand anything any better. Are they both actively suppling current on the same circuit simultaneously? Are there two circuits, one for each? Is one a redundant altenator which only activates on failure of the primary or based on increased demand? Will having two help keep my RV batteries charged better while in tow? What do I need to know about having two alternators?

[tuffr2]

I can not answer your specific questions but can tell you it is a 'good thing'.

[onechaddude]

Yes it will help charge your RV batteries better....if you have a larger cable running to the back to charge the batteries. The factory wire in the 7 pin plug is I think a 10 gauge with 30 amp fuse. That's a decent size but with the losses in the plug and such will take a long time to recharge 1 battery, let alone a bank of batteries.

As for how its wired, I think I read both alternators are supplying juice to one central source. It's an option available to supply extra power for things like a snow blade or dump bed and such. Also, with a thick gauge cable to the RV, would be handy to recharge a battery bank fast.

Chad

[Arch Hoagland]

Watching this thread as I'm curious about it too.

[tuffr2]

That is a good point about a snow plow blade. The dually truck, that I had, had 2 alternators and also had the snow plow package along with six or so outfitter switches.

Now I wonder if it was the snow plow package that added the 2nd alternator.

OP - does your truck have a snow plow package?

[laj]

the snowplow pkg. has nothing to do with dual alternators. dual alternators are an option by themselves.

[RoadEyePie]

Originally Posted by tuffr2

That is a good point about a snow plow blade. The dually truck, that I had, had 2 alternators and also had the snow plow package along with six or so outfitter switches.

Now I wonder if it was the snow plow package that added the 2nd alternator.

OP - does your truck have a snow plow package?

I don't think so. If it does, it didn't include the plow.

[Intothewild]

I have thought about adding a second alternator , batteries and inverter and getting rid of my generator

[marks146]

I have dual alternators,too. That's how the dealer ordered it, and I bought off the lot. I think I'll sit back and learn of their virtues.

[RoadEyePie]

Originally Posted by marks146

I have dual alternators,too. That's how the dealer ordered it, and I bought off the lot. I think I'll sit back and learn of their virtues.

It doesn't appear that a lot of folks know much about this subject. I also bought the vehicle off the lot as is with whatever the dealer ordered. It had everything I wanted plus a few extras like the dual alternators. I know they are installed in emergency vehicle and vehicles with snowplow operations. I just want to be sure that the second alternator isn't sitting there doing nothing because I don't have the snowplow option. I'm going to call the dealer service department next week and learn what I can.

[laj]

the issue is quite simple. a 150amp is standard, 220amp the single option, and if you want the dual option you get a 150,and a 220. the purpose is strictly to cover whatever electrical load you put on the system so as to not drain the battery.

[nvs4602]

Originally Posted by Intothewild

I have thought about adding a second alternator , batteries and inverter and getting rid of my generator

You can buy higher amp alternators for your truck. I just swapped out my 135 amp OEM to a 250 amp in my chevy avalanche. As for the dual alternators they just supply more juice amps for running lights and such like on emergency vehicles. Also great if you run a high end stereo system.

[RoadEyePie]

Originally Posted by laj

the issue is quite simple. a 150amp is standard, 220amp the single option, and if you want the dual option you get a 150,and a 220. the purpose is strictly to cover whatever electrical load you put on the system so as to not drain the battery.

So when you have dual (as I do), is the second one only supplying current when demand is high, sort of peak demand or are the two constantly sharing the demand. I guess I don't really have a fundamental understanding of how alternators work. I know what they do, just not really how they do it.

[DG N. AL]

Both are constantly supplying current to a common system. A dual step is common on construction and Ag equipment that have higher electrical demands.