Adding second alternator ISM-500

[d23haynes57]

Looking to add a second alternator for dedicated charging house batteries and running AC while driving. Anyone has information on brackets or kits? Cummins Engine, ISM-500 2008.

[Unplanned Tourist]

Why not just upgrade the existing alternator?

[d23haynes57]

Looking at 24 volt option for larger House Inverter Loads. Multiple alternators common on many Prevost-Newels.

[jacwjames]

Out of curiosity I did a bunch of searching about adding a second alternator to first and ISM, came up with nothing. Then adding a second alternator to Cummins engine, none on motorhomes but there are alternators added to larger pickup engines.


Found one site that had kits for up to 4 on pickups.



https://www.nationsstarteralternator...urxXaaX2g9gwyo


I do remember one coach owner that did away with his hyd cooling fan and went with multiple electric fans which required adding at least one alternator. This was on a CAT engine but the concept is the same. This guy is pretty sharp.





https://www.irv2.com/forums/f115/eng...-529456-2.html
There is a video on the 2nd page of posts.



https://www.irv2.com/forums/f115/ele...dp-557437.html


He has now moved up to a Prevost with a Detroit engine, playing with the big boys now.

[SafariBen]

Supposedly cummins is or has already come out with a seperate 48V alternator just for heating the emissions. One of those would be fun to play with.

[Alpine36]

Thinking outside of the box, maybe a remote 24v hydraulically driven alternator may be something to consider. Whatever you do it’s going to be a custom application anyhow. Google “Harrison hydragen” for some hydraulically driven generator ideas. We used these with positive results on our electric utility truck builds @120vac, but I’m not sure if they produce a 24vdc model.

Option number two…years ago I did a lot of custom hydraulic system installs with a company by the name of Harper Industry’s (aka Deweze)
They fabricate all sorts of custom engine brackets for belt driven remote mounted hydraulic systems. They may offer a mounting bracket for your engine that could be customized for alternator use.

Or, break out the mig welder with a little C.A.D. work.
(Cardboard aided design)
I’m going to quote my favorite senior mentor while serving my mechanic apprenticeship in the 70’s…
“With enough time and money we can fix anything”

[m0v1]

I have been juggling alternators around on our Series 60. I am going to need extra alternator power for additional electric cooling fans as I turn up the power output of the Detroit.

The next configuration will be a 400amp 24v alternator in the original bracket for the DN50 and a 200amp 12v air-cooled Bosch unit where the AC compressor was located. It looks like it will be very easy to adapt the existing compressor brackets/belts to mount an alternator.

The dash air will then be converted to a 24v electric compressor which will be located behind the front bumper with a new condenser coil. This will put these components right where they need to be and provide a new capability. We will be able to run the dash air from solar and battery power when dry camping. Sure, it won't cool nearly as much as the rooftops, but will be a fun experiment and may be a nice option in certain scenarios.

Maybe a little more wild than you were thinking, but thought I would throw my crazy plan out there for someone else to try too!

[hypoxia]

Originally Posted by d23haynes57

Looking to add a second alternator for dedicated charging house batteries and running AC while driving.

Is there a downside to using the generator?

[Tony Ramirez]

Originally Posted by hypoxia

Is there a downside to using the generator?

THAT can of worms has been opened multiple times. All kinds of threads arguing for & against.

[d23haynes57]

Originally Posted by jacwjames

Out of curiosity I did a bunch of searching about adding a second alternator to first and ISM, came up with nothing. Then adding a second alternator to Cummins engine, none on motorhomes but there are alternators added to larger pickup engines.


Found one site that had kits for up to 4 on pickups.



https://www.nationsstarteralternator...urxXaaX2g9gwyo


I do remember one coach owner that did away with his hyd cooling fan and went with multiple electric fans which required adding at least one alternator. This was on a CAT engine but the concept is the same. This guy is pretty sharp.





https://www.irv2.com/forums/f115/eng...-529456-2.html
There is a video on the 2nd page of posts.



https://www.irv2.com/forums/f115/ele...dp-557437.html


He has now moved up to a Prevost with a Detroit engine, playing with the big boys now.

I am very familiar with Nations. I am looking at this as a possible option as a bolt upgrade. It should fit with pulley change.

https://www.nationsstarteralternator...00-12v-430.htm

They also offer a 24-volt version.

Part of my concern is that for this current you are still limited to that single terminal connection. I can see that as always being a Limiting factor. Currently I have a 270-amp, and it is working fine charging a 900 A/H bank using the original Foretravel Diode Isolator. I know that if I out an AC on it that combo will be too much for the alternator and diode set up. I would need to control that the AC does not get turned on until the batteries are near fully charged. One or the other.

[PushedAround]

Originally Posted by d23haynes57

Looking at 24 volt option for larger House Inverter Loads. Multiple alternators common on many Prevost-Newels.

Were you planning on wiring the alternators in series to get 24V? If so, any concerns about internal groundings in the alternators?

[d23haynes57]

Wouldn't give that any thought. 24-volt alternators are readily available and many busses, trucks use 24 volt systems. 24-volt 500 amp! 12K from the engine. That would be sweet.

[PushedAround]

Sorry for being dense here, but you would use the 2nd alternator for the 24v system and keep the existing for the 12v systems.

One thing that sounds sweet is to replace the radiator fans with electric units now that you would be freeing up electrical capacity (or would that be 24v too?).

[d23haynes57]

Originally Posted by PushedAround

Sorry for being dense here, but you would use the 2nd alternator for the 24v system and keep the existing for the 12v systems.

One thing that sounds sweet is to replace the radiator fans with electric units now that you would be freeing up electrical capacity (or would that be 24v too?).

You're not being dense at all. No apologizes needed.
If I was to do this my plan would be to keep all the 12 volt chassis and house systems in place as is and use the 24 volts for dedicated battery bank and inverter(s).

For the most part, my system does what I need now except AC requires generator or shore power. My existing battery bank carries me through a weekend even in cold weather and with the 150-amp charger I can recover daily use in 1 or 2 hours of generator time.