Only negatives are the extra $400 and slightly decreased space in the engine bay. That's it. Practically zero effect on MPG and they are not prone to fail.

Sounds like this is an option that is a no-brainer for you as it will future-proof your truck.

 

I don't see how it could be a negative. I wish they would offer a compressor instead of the second alternator.

 

A compressor would be awesome, and maybe an ejection seat for the passenger like James Bond had

Thanks for the help.

Are they setup in some crazy way that I really only have 220A but redundant or will each produce X amps at a certain rpm so that at that RPM I have 2x?

Are they off on one belt?

 

The second one has a propeller on it, and is driven by the wind from the fan.

 

Mean Green makes a 300 amp gen. A decent compromise.

 

Only downside I can see is your probably not going to find that serpentine belt at all the auto parts stores.

I would carry a spare with me. Although that is a good idea with the normal belt as well.

Otherwise, for winching, I would say the dual alternators would be great.

 

Funny several months ago my truck slung the belt off while my wife and son were on the way to lake murray SC (water pump went next) for one his fishing tournaments. I got off work went up there and every auto store I went to only had the dual alternator belt in stock. Got one that was about and inch longer than the regular belt to make it home. My luck I guess. :confused013::confused013:

 

GlennRMK

that is a great suggestion. I was thinking the same..Cant be that expensive and even if it is not bad to have and will eventually get used. Dont think I would be able to put one on in the field but if I have some tools I bet someone else can

 

I think you'd get no/little benefit. Two batteries and the output of your one alternator will meet your need. The purpose of the second alternator is to provide durable power for long-running auxiliary equipment that requires, more than say 1,800 watts - a large refrigeration unit for instance.

Aside from the belt issue - addressed by carrying a spare - just like a 2 engine airplane, you double your chance of failure of a critical item.

 

I think you'd get no/little benefit. Two batteries and the output of your one alternator will meet your need. The purpose of the second alternator is to provide durable power for long-running auxiliary equipment that requires, more than say 1,800 watts - a large refrigeration unit for instance.

Aside from the belt issue - addressed by carrying a spare - just like a 2 engine airplane, you double your chance of failure of a critical item.

I agree. 220A and two batteries is nearly double just about every purpose-built offroad buggy/truck out there that winches a lot more than you probably will.

 

I wouldn't consider the serpentine belt availability a big deal. I've never seen a properly maintained serpentine belt break without some major accessory malfunction.

 

I saw no downside to the dual alt option other than the buy in cost. Seems like a highly desirable option.

 

The negative to the dual alt option is that you're going to want to power more things off of your truck. Really no downsides.

 

To me, it's just something else to go wrong. Anything that runs off the belt is a potential breakdown point.

 

I run my 12k winch off one marine 12v battery, 31 series I think, no alternator. It will drag a vehicle sideways through dirt without effort. You'll be fine without the second alternator.

 

Depends upon how much you want to winch.

From Warn's web site for the 16.5ti model winch:

12V DC PERFORMANCE SPECS
Line Pull Line Speed Motor
Lbs.(Kgs.) FT./min(M/min.) Current
0 23.6(7.20) 68 amps
2000(907) 12.07(3.68) 138 amps
4000(1814) 9.22(2.81) 189 amps
6000(2721) 7.37(2.25) 240 amps
8000(3628) 6.08(1.85) 291 amps
10000(4536) 5.12(1.56) 342 amps
12000(5443) 4.40(1.34) 393 amps
14000(6350) 3.86(1.18) 444 amps
16000(7257) 3.38(1.03) 494 amps
16500(7484) 3.24(0.99) 507 amps

You'll want some monster cables to the batteries/alternator at those high amps though.

 

I personally don't like the dual alt option and advise against it for the following reasons. 1 - the belt is hard to get and more expensive. 2 - it makes it more crowded and harder to get to things for service. 3 - (the biggest reason) if you understand the cable and connection requirements needed to get 440 amps anywhere past the batteries you'll probably not make the attempt. The batteries act as reserve power for all kinds of things including winching. 4 - I suspect the extra drag/tension on the belt can help with water pump failure (my speculation).

Ultimately it's your truck and that's what matters most. Take the opinions and advise to whatever level you feel suits your situation and needs then pull the trigger. The truck definitely won't explode if you decide to get them....

 

I have a single alternator and a 16.5 Warn winch
I had to winch my skid loader yesterday and the truck handled it fine. It was not a long pull. Since you have the availability to get dual alternators for your usage I would suggest doing so. To me 400.00 is a no brainer and is not much for the added power when needed
I spool and stretch a few new winches each month and I have seen some check engine lights come on because the electrical system cant keep up. I do rev the engines to about 2000 RPM for more output than at idle

 

...
I do rev the engines to about 2000 RPM for more output than at idle

If I'm reading RAM's alternator specs right, with a pulley ratio of 3.22, the 220A alternator will be running at 6440 rpm and putting out 425A approx. when the engine is at 2000rpm.

Ideally, you should have big cables to handle that,at least 4/0, the ampacity wire charts I've seen stop at 360Amps and 4/0 wire gauge. So yes, keep those heavy pulls fairly short so the wires don't melt.

This would all be a lot easier if the truck had a 48V battery system.

 

If you are buying a tow truck and plan on doing vehicle recoveries all day long you need dual alternators, for self recovery with a bumper mounted winch a single 220 is more than enough.

 

I have an 07 Power Wagon, now it only has 1 battery and only a 200amp (I think) alternator, but definitely get the second alternator option. A lot of the guys on the Power Wagon forums have the option and it greatly helps when doing hard pulls. I've done may pulls with my truck, and I can have the amp gauge in the truck in complete discharge and stall the winch out. Now these are VERY hard pulls but I've had to pause and let the alternator catch up and then continue pulling. As mentioned above winching like I have had to do, and pulling the battery down fast and hard is really hard on them.

 

Helps to have 2 batteries also. I have a 300 amp single and a 16k winch is no problem.

 

We need a clearer idea of the auxiliary/winch demands - how many amps, for how long, and how long between winches.

 

I had Warn 9000# on my old Ford F350 4x4 for 16 years and I used it a lot off roading in the swamps hunting and playing in the mud. I used to say that looks deep, is there a tree over there if i don't make it. LOL I wished more than once that I had dual Altenators and bigger AGM batteries.
I say go for it and don't look back. Use welding cable for winch to battery hookup 1/0. Use a snatch block when you can for easier strain on electrical.
Use Oddesy AGM batteries will be a nice storage bank of power when the Altenators can't keep up.
The factory lead/acid batteries don't have much storage like a deep cycle AGM battery.
Post picks of your new truck and don't forget your new Ram power management system sucks in loose dirt and mud and you will need that winch a lot if you go off road because Ram and mud dont get along.

 

Exactly. I blew a water pump and it of course took out the belt. I had to wait two extra days for the dealership to get the longer belt shipped in. Since then I bought a spare.

 

For anyone who has ever done any significant amount of winching, you will know that heavy duty Alt are needed. The single 220a alternator is not enough for a heavy duty 16.5 lbs winch. watch the battery voltage when winching and you will quickly see it drop to 9.5-10 volts. Sure it will work to pull the truck off a patch of snow etc., but if you bog down in heavy mud, need to pull up a section of hill etc. the winch will strain and likely kill the battery not to mention decrease the life of the battery. If you plan on heavy winching without a doubt get 2 alternators.

Negatives of 2nd alternator: Cost, tighter engine room and potentially harder to find a belt on the road as others have already mentioned.

 

Dual alternators will def help with winching and help the batteries as they will not get drained. Did a lot of 4wheelng in my younger days and while a lot of winching with a good working battery and alternator never had any real issues, if it was a long hard winch boy you feared the motor stalling because the battery might be to drained to start back up. If you actually plan to do a lot of winching, bigger and FASTER is the way to go, even with two alternators a bigger winch will not have to work as hard, and faster will mean a lot shorter winching times.

 

electricity is confusing

 

Fun with numbers:

1) using conservative numbers: You'll have 2 batteries that together have an amp hour capacity in excess of 200 amp hours. That output (as long as we're within the CCA capacity of the batteries which will be well over a combined thousand amps) is ~equivalent to 400 amps for 30 minutes. Now, in the interest of not greatly abusing the batteries lets plan to draw a max of 10% of the available amp-hours. That leaves us with 400 amp draw for 3 minutes.

2) Now lets look at a winch. Here's one - a little light perhaps, but it'll do to explain the analysis:

Line Performance (First Layer of Cable)
Line Pull (lbs) Line Speed (fpm) Amp Draw
0 16.4 72
2,000 14 115
4,000 9.9 159
6,000 9.1 198
8,000 7.6 242
10,000 6.1 281
12,000 5.0 320

Note that at 12,000 lb load the line speed is 5 FPM - and note that at half that load the line speed is almost twice as much, (9.1 FPM) but the amp draw has dropped from 320 amps to 198 amps. So, you loose just a little winching speed (about 5%) if you use a snatch block and you'll significantly reduce both the amp draw and amp-hour draw by using a snatch block. So in choosing a winch - one about as powerful as it needs to be in direct pull will provide good electrical benefits if operated with a snatch block with essentially no loss of retrieval speed.

3) So let's imagine a winch that with a snatch block will draw 400 amps. Clearly a pretty powerful winch. How does it performs on our truck? How much current might be supplied from our 220 amp alternator? Let's say our truck with no accessories running requires 50 amps (it won't be nearly that high) and lets allow a 20 amp safety margin, leaving 150 amps for the winch from the alternator. That leaves us needing 250 amps for the winch. Looking back at point 1 above we see that we can safely draw 400 amps from the battery for 3 minutes - twice as long if we draw 20% of the battery's capacity.

4) You might also notice the winch likely has a duty cycle - ie, must have a period of rest between periods of use that have some maximum time. For example, lets assume the winch can be run for 1 minute and then must rest for 2 minutes - a duty cycle of 1/3. In this case the alternator is charging the battery while the winch is cooling; the alternator will, over 3 minutes, be recharging the batteries during the rest period thus effectively supplying 3X its apparent amp-hour rating.

Things aren't quite this simple, but it's easy to see that a 220 AMP alternator and 2 batteries, can safely power a significant winch. If the load (winch) requires rest periods there is no reason to have alternator capacity approaching the amp draw of the load - at most, the amp-hours needed over the full working period is appropriate. There is a calculable optimum combination of battery capacity and alternator capacity for any situation. Greatly increasing the size of either the batteries or the alternator beyond the optimum value of each for the job at hand, provides little benefit. If you have a winch that you want to run continuously for, say, 15 minutes at high amps, then you do probably need twin alternators, but if you're winch requires rest periods or only needs to be run a few minutes, then you likely will realize no winching benefit from a second alternator.

 

...
Things aren't quite this simple, but it's easy to see that a 220 AMP alternator and 2 batteries, can safely power a significant winch. If the load (winch) requires rest periods there is no reason to have alternator capacity approaching the amp draw of the load - at most, the amp-hours needed over the full working period is appropriate. There is a calculable optimum combination of battery capacity and alternator capacity for any situation. Greatly increasing the size of either the batteries or the alternator beyond the optimum value of each for the job at hand, provides little benefit. If you have a winch that you want to run continuously for, say, 15 minutes at high amps, then you do probably need twin alternators, but if you're winch requires rest periods or only needs to be run a few minutes, then you likely will realize no winching benefit from a second alternator.

But you may save your batteries. The question comes down to how much and for how long do you want to draw down your batteries.

The Starter batteries in our trucks do not like being drawn down much, and the more you do the more you will shorten their lifespan. Wikipedia sums it up pretty well:

An automotive battery is a rechargeable battery that supplies electrical energy to a motor vehicle. It is also known as an SLI battery (starting-lighting-ignition) [1] and its main purpose is to start the engine. Once the engine is running, power for the car's electrical systems is supplied by the alternator. Typically, starting discharges less than three per cent of the battery capacity. SLI batteries are designed to release a high burst of current and then be quickly recharged. They are not designed for deep discharge, and a full discharge can reduce the battery's lifespan.[2]

As well as starting the engine an SLI battery supplies the extra power necessary when the vehicle's electrical requirements exceed the supply from the charging system. It is also a stabilizer, evening out potentially damaging voltage spikes.[3] While the engine is running, most of the power is provided by the alternator, which includes a voltage regulator to keep the output between 13.5 and 14.5 V.[4]