Dual alternator.....

[oscarvan]

Does anyone have a dual alternator setup on the ISB 6.7 engine?

I'm looking at pictures of RAM trucks with an additional alternator on the top left side (for them with a normal forward facing engine) above the power steering pump.....

Looks like a matter of brackets and a longer belt.....

Would love to see pictures and possibly a parts list.

[Oregonpharme]

Having been the victim of Ram's 6.7 diesel dual alternator setup, I suspect you do not want that type of system anywhere near your coach. I converted the 2017 Ram 6.7 to a single 220 amp alternator, and no more frequent trips to the dealer for programming and repairs.
Really explore your options for a higher output alternator if you need more amperage before you jump on that dual alternator train.

[oscarvan]

Originally Posted by Oregonpharme

Having been the victim of Ram's 6.7 diesel dual alternator setup, I suspect you do not want that type of system anywhere near your coach. I converted the 2017 Ram 6.7 to a single 220 amp alternator, and no more frequent trips to the dealer for programming and repairs.
Really explore your options for a higher output alternator if you need more amperage before you jump on that dual alternator train.

I am also looking at that.....

The reason I am thinking dual alternator is because, unlike your Ram, we're talking two completely separate systems with separate banks and separate demands here.

I plan on significantly increasing the house DC load, ie running one AC on my inverter while driving. The chassis battery would be as always, but the second alternator would be working a lot harder keeping the bank full.

Yes, I would need an alternator suited for continuous high load and an inverter suited for it's job. Got all that.

What I would really like is a second alternator on it's own belt off the crank case.... Double up on the pulley there...

[Oregonpharme]

I understand the need, when I am done spraying today I will take a photo of the marine isolater and charge controller I put on my boondock motorhome. Hopefully I will be able to post it, but that unit allows the high output engine alternator to charge the house batteries without the risk of too high a charge rate and overcharging.

Motorhomes that directly charge the coach batteries from the high output engine systems really shorten the life of the coach batteries because deep or extended cycle batteries take a lower charge rate and must have a tapering system to slow the charge as they reach capacity. The chemical composition of the battery designed for extended draw is different than those used as engine starting batteries, and can be damaged with too much initial charge and overcharging. The automotive alternator systems are not designed to accomplish that goal, they rapidly charge then cut the rate at somewhere around 13.8 to 14.3 VDC.

[oscarvan]

Yeah there already IS a BIM (Battery Isolation Manager) that I will have to figure into the equation. In fact with a dual setup I may have to NOT connect the two banks.

If I stay single high output not sure where to go with existing BIM. Current alternator is 130A, and when paralleled is putting 100 or less in the house bank which is OK charge rate for a 450Ah bank. 400 or so would not be.

This setup has been running for 2-1/2 years no problem now. I do have to water the batteries frequently even though my plugged in charge rate is set at 50% (50Ah)

But, what I am planning on will be relatively high draw.... as in 12VDC, 125A-ish, but only when engine is running. So battery bank would be full, and I want most of alternator output to go straight to load. Bank would act as buffer.

There are setups like this in use in emergency vehicles etc. I just have to talk to the right people.

[Oregonpharme]

I did not make it in from farming until after 9 last night, so will try to get a photo of the system today. It will do what you want with a single high capacity alternator without the potential for deep cycle battery damage that occurs when that type of battery is used as a wet capacitor to stabilize the load.

Took the photo while the tractor is warming. But, cannot get it to post. PM me with your email and I will send the photo. The device is a Pro Charge B, it directly connects to the engine battery, eliminates the original isolater, and then connects to the deep cycle bank.

No more boiling deep cycle batteries dry or overcharging the deep cycle AGM type I now use.

If I am running a heavy draw on the deep cycle batteries, the Pro Charge B simply increases the amperage from the alternator without stressing the battery plant.

[oscarvan]

Aaah..a B2B. The Sterling people. Yes they know what they're doing. Use those in van conversions to keep CAN chassis and DIY house system separated. Cool, thanks. PM sent.

[oscarvan]

So the BIM that's in there, by Precision Circuits is rated to 225A

Talked to their tech support people and they said upgrading the alternator and putting a high load on the system would work just fine.

[RAM 6.7 4x4]

Originally Posted by Oregonpharme

Having been the victim of Ram's 6.7 diesel dual alternator setup, I suspect you do not want that type of system anywhere near your coach. I converted the 2017 Ram 6.7 to a single 220 amp alternator, and no more frequent trips to the dealer for programming and repairs.
Really explore your options for a higher output alternator if you need more amperage before you jump on that dual alternator train.

What should I be aware of with this configuration as the Ram we have has the dual alternator setup, bought the truck used with 2500 miles on it and it came that way. So far we've had no issues to date with that configuration.

[Oregonpharme]

Originally Posted by RAM 6.7 4x4

What should I be aware of with this configuration as the Ram we have has the dual alternator setup, bought the truck used with 2500 miles on it and it came that way. So far we've had no issues to date with that configuration.

The electronic control module for the alternators is the same ECM that controls the engine. As the alternators wear and voltage output fluctuates, the ECM becomes unable to do its function and the system sets error codes. My Ram went into "limp home" mode so many times I got rid of it as not being worth the hassle.

Now there are now kits that replace the two anemic units with a single heavy duty unit, but the dealer must reprogram the ECM to eliminate the dual setup to enable the conversion. If I still had the Ram, I would do the conversion as soon as I experienced a problem with the dual setup.

I have had other equipment with dual alternators that did not have ECM control, and as one alternator wears differently than another, the voltage and amperage becomes unpredictable and causes fits with electronics associated with GPS field control.

Dual low cost OEM alternators were once viewed as an inexpensive means to boost the available amperage, but over time that has not proven to be the case. I suspect the problems led to discontinuance of that scheme.

[oscarvan]

For the record, my second alternator would be completely separate from the chassis and strictly for the house bank for the very reason of NOT messing with the chassis/ECU etc.