400 amp alternator, Niehoff, installing

[Gunny65]

I am converting my rig into a camper. I believe the amp break down, on the 400 amp alt, is 350amps at 28v and 50amps at 14 volts. It is a Niehoff and has the regulator with it. I have the cta8.3 Cummins engine with no extra goodies installed yet. It looks like it will fit, with maybe a few mount mods. Looks close though. Wiring wise, are there any problems Hooking this up as is?

I am am going to have a 4 each 225mah batteries for coach power. I was thinking, with a 24 volt step down and a good inverter, this would recharge the battery bank much better. Since it already has a regulator, I don't see any issues with electrical...but...I also am not a electrician or a mechanic. Oh, and I am using the standard 4 each vehicle starting batteries as well, if that makes any difference.

Thoughts? Is it as straight forward as it seems?

 

[74M35A2]

The dual-voltage ones are not the most reliable units. Also, that is a very heavy and large alternator. The stock military and civilian alternator bracketry is not up to the task of supporting that unit correctly through vibration, etc.... Also, 8 batteries is almost enough to make it a hybrid vehicle! But, that is a personal decision. If you plan to use them a long time, then I can sort of see it. Make sure you use a battery isolator or high current switch to not kill your starting batteries. I'd chose a quiet Honda EU2000 generator instead, but that is personal preference. It is probably nearly the same cost, can go other places as well, and never goes dead.

 

[Wildchild467]

opcorn:

 

[Gunny65]

74M,
I plan on boondocking often. That is the reason for the four 225mah batteries. I want to have plenty of battery storage and since I do not have a regular generator, I wanted a larger Alt to help out in the recharging area. An inverter with smart charge capability will be installed as well. I will start out with 2 of those coach batteries and then upgrade to four later on. The Van will run off both 12volt dc and for the most part 120volt was well. The cab and rest of truck will remain 24volt. I am going to isolate the coach batteries from the starting batteries. Most of the high intensity lights I have are 24 volt. Does any of that require a 400amp alternator? No. However, the price difference between the 200amp and 400amp are, if not the same, very close. If I am spending that kind of money on a "generator" then I figured I would go with the higher amps. The only thing I am worried about is electrical issues. From what I understand the regulator does a good job of keeping the electrical in line. I think the higher amps will also charge the batteries quicker. Yes, no? I don't know. I am hoping this thread will clear some of this up for me. I have read a lot of the 200amp changeover threads on here but nothing specific on the 400amp version and problems to look for. I am not looking for approval after the fact. I really do want to know what problems I need to be aware of. I do know I will need to fabricate mounting brackets and upgrade some wiring.

One other thing, can the alternator's 24volt side be used in some fashion to charge the coach batteries? (maybe using a 24v step down?) And, will the 24v side charge those coach batteries quicker using those higher amps? It seems to me that it would.

Thanks.

 

[74M35A2]

For battery recharge, batteries will only accept as much charge as they "want", so by being able to supply 400A does not mean they will take it. This is something a lot of people don't get. It depends on their discharge level. A completely dead battery accepts very little current at first, then a lot, and then back down to a small amount as it nears full. For the system you are wanting to do, I'd run 2 separate alternators, a high quality 12v and 24v. A few people have easily adapted dual alts to the 8.3, easily, and there are pics. Not very practical to charge 12v batteries (not connected in series) from a 24v source in a regulated and automated fashion. Just my opinions, others may differ. As a data reference, I measured the battery recharge current after a warm start of my 8.3, and the peak was 15 amps, which quickly curved down to near zero. That is with 2 x group 31's brand new. I know that is different than you intend how to use them.

 

[simp5782]

This may help? But I dunno. I had the same thought for this 934 box that I have but then again ill probably just hook a mep to it.

 

[Gunny65]

I have a mobile MEP but I would have to pull it. I have a car trailer to pull with no extra room on it for the MEP. For the short term, the 400amp dual will have to work as my charger.

 

[fiero11]

Gunny65, Did you get the 400 amp Niehoff wedged into your truck? I have an M923a2 with the Cummins 6CTA turbo 8.3L engine that I am wanting to put a Niehoff 450 amp generator in. I bought a 200 amp Niehoff upgrade kit for brackets to accommodate the larger size and weight and Niehoff sent me a blueprint of the generator so I could check size and specs. Like you, I determined that it will fit with a bit of work and relocating some hoses. I am not camping, but I wanted the bigger size generator to power an EyeCon 360 HID light kit and a large power inverter. Also like you, the 200 amp Niehoff would fit fine, but the 450 and 400 amp Niehoff's were half the price. Did you determine if the wiring connections are different? The upgrade kit had some good parts but no instructions, so I'm a little lost. Any help you or others can offer would be appreciated.

 

[Csm Davis]

Gunny are you going to run a 24v inverter? That would be a good setup for the house side forget the 12v side for anything outside of the cab. 24v is used for some really nice off grid setups so that would be the direction to look at for the house side. If you want to run more than a radio and cell phone off the 12v side do like 74M35A2 suggest and run a separate 12v alternator. These high amp 24v alternators are mainly for communication trucks with huge amperage draw for radios and contact trucks that need to jump-start big trucks or maybe aircraft. I am not saying don't do it just trying to understand the use you are going for to try and help.

sent from my decrepit fingers

 

[FloridaAKM]

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