Dual vs single alternators

[Marathonman513]

I have a Montana High Country 377FL and am looking to purchase a new GMC Sierra 3500 with a 6.6L Duromax Diesel engine. The one I want has a single alternator but there is another one with a dual alternator but I don’t like it as much. Does anyone have experience with this?

 

[MandK]

Dual alternators are put on trucks that may have to power a lot of accessories like plow pumps, salt spreaders, light bars, chassis for ambulances, wreckers etc. If a Ford is equipped with a supplemental cab heater, it will have the dual alternator option as part of the heater option. I think Ram is the same. I am not familiar with GM trucks, but as long as it has enough alternator to take care of regular stuff you need and an extra 80 amps or so to possibly supply a dc/dc charger you may want someday, go with the truck you like the best.
My truck has the dual alternator option because it has the supplemental rapid heat cab heater. So did my last one. Instant heat.

 

[Daryles]

We have a 2016 F350 Super Duty crew cab Lariat. It has dual 200A alternators and an onboard 400W inverter to run small 120vac devices. I installed a 60A DC-DC charger. It works very well.
I found out later with dual alternators, the secondary alternator does not kick in until the primary reaches about 80% capacity.
For us, even with everything running (400w inverter, 60a DC-DC charger, AC on max etc.) the primary 200A alternator will run everything.

 

[BBaloo]

I have a Montana High Country 377FL and am looking to purchase a new GMC Sierra 3500 with a 6.6L Duromax Diesel engine. The one I want has a single alternator but there is another one with a dual alternator but I don’t like it as much. Does anyone have experience with this?

My truck is a 2022 RAM 3500 with the dual alternators. They are set up in parallel. That is, they both operate to share the load. One does not lay idle while the other is lightly loaded. I agree with the others, that if you do not ever have a need for additional large draw loads, then one alternator is more than adequate. My setup is dual 220A, totaling 440A. I have a quick disconnect setup to serve my winch, or any other load I wish to connect. Also just keep in mind that when we are hitched, our RVs can only pull a max of about 30A, due to the fuse setup and the wiring connection from our tow vehicles. That's why most trucks only have the single alternator. You might have already gone ahead with your purchase, but I would make sure the single version alternator was larger than 200A.

 

[Marathonman513]

Thank you for your replies as they helped me in my selection. I ended up going with the Sierra 3500 with the single 220amp alternator because it had everything else that I wanted.

 

[Derby6]

Should have got a ford. Lol
Kidding. Congrats.

 

[mlh]

Great truck. I’m sure you will love it.
Lynwood