High Amp Alternator Suggestions

Hey all,
I’d love to put a 200 amp, twin belt marine alternator on my Cat 3406. I can fabricate the mount brackets if needed. I’m just looking for some good sources that some of you have found?
In doing my searches online, the prices tend to be very high.
Any suggestions on a source that is reasonable?
Many thanks,
Taras

Taras said:

Hey all,
I’d love to put a 200 amp, twin belt marine alternator on my Cat 3406. I can fabricate the mount brackets if needed. I’m just looking for some good sources that some of you have found?
In doing my searches online, the prices tend to be very high.
Any suggestions on a source that is reasonable?
Many thanks,
Taras

Click to expand...

What size alternator do you have now?
You want to add a second alternator? I suspect you will need to change the battery charger etc but, I will yield to someone who knows something about this.
How many and what size are your batteries?

For high amp alts it is hard to go past Leece Neville. I have 200A on each engine, and a spare that's still wrapped up, not been used in 6 years. We replaced the std John Deere alts, beefing up the mounts, but no belt change.

Insequent said:

For high amp alts it is hard to go past Leece Neville. I have 200A on each engine, and a spare that's still wrapped up, not been used in 6 years. We replaced the std John Deere alts, beefing up the mounts, but no belt change.

Click to expand...

Excellent advise, I have also had great luck with LN alternators
HOLLYWOOD

Taras said:

Hey all,
I’d love to put a 200 amp, twin belt marine alternator on my Cat 3406. I can fabricate the mount brackets if needed. I’m just looking for some good sources that some of you have found?
In doing my searches online, the prices tend to be very high.
Any suggestions on a source that is reasonable?
Many thanks,
Taras

Click to expand...

I have a 250A Zena with an external rectifier bridge. It's controlled with a Balmar 612. I duct outside air from a 250 cfm blower into the back of the alternator, it can run full field for hours and I've never seen it go over 100*C. I have the Balmar temp sensor installed. The Zena is basically a Leece-Neville on steroids. Mine's driven by an 8-ribbed serpentine belt on a Cummins 6BT. It has been a great addition, eliminating a chronic undercharge problem. My 1150 AH bank can go from 60% SoC to float in a typical day's cruise (~6 hrs or less). My underway 12V load is about 60A, so a 100A alternator just won't cut it! Not inexpensive at just over $1K, but it was worth the money. That's reasonable in my book.

An excellent read on tis subject:

https://mvdirona.com/2018/12/13-2-kw-alternators-and-beyond/

I suggest you google 50DN alternators.

These can be had from 200A 12V to 450A 24V either belt driven (flat belt for big output) or directly engine driven . Air or engine oil cooled.

Happily they have external regulators so are an easy install for a 3 or 4 stage Volt regulators.

They are the standard of the bus industry for many decades so great rebuilt units can be had with no core charge.

They ARE big and heavy.IF you are in FL , come on over and you can have a 220A 12V unit.

THe best deal on 135-140A HD alts is at the DD dealer , about $135 , plus the pulley of your choice.

I bought a back up alternator ... standard size for the AT's Cummins QSB 5.9. If something happens, it is just "cut and paste" quickly.

Very happy with my Leece Neville 220 amp alternator. Here is the setup I put together on my 4045 John Deere.

Ted

If cost is a factor, I use GM CS-144 alternators. 140 amp stock and there are kits to rebuild or increase amperage. They're about $30 used or $100 new on ebay. Also 200 to 300 amp versions for about $300. They need either dual belts or serpentine. I have them on my Detroit mains and 2 generators plus and additional one modified for 48v.

Here's a 200A Externally Regulated J-180 Mount alternator for a reasonable price.

Taras said:

Hey all,

I’d love to put a 200 amp, twin belt marine alternator on my Cat 3406. I can fabricate the mount brackets if needed. I’m just looking for some good sources that some of you have found?

In doing my searches online, the prices tend to be very high.

Any suggestions on a source that is reasonable?

Many thanks,

Taras

Click to expand...

If you don’t have room for large frame alternators, check these out. I have had good luck for over 5 years with these. I charge a 940 amp bank.
https://www.qualitypowerauto.com/category_135/Mega-Amp-Alternators--Custom-Billet-Cases.htm

Thanks for all the great suggestions thus far! Many of you suggested alts that did not come up on any of my searches, so I appreciate the help.
To answer the question, I will be replacing the stock 75 amp Cat alternator. I’ve got about 1000 AH of house bank I’m trying to charge with a high amp alternator replacement, thus the 200Amp I’m thinking of purchasing. I’m obviously trying to reduce my Gen set run time while cruising. I really appreciate the knowledge here��

At 200 amps, I would only get a large frame alternator.

I'm using an externally regulated Ample Power small frame 130 amp marine unit on one engine because a large case Balmar unit wouldn't fit. But I have a related question... I attempted to dump the output of the 65 amp alternator on the second engine into the house bank and then add a Blue Sea device to dribble power into the start bank...or maybe it was the other way around. Anyway, the old internally regulated alternator kept blocking/shutting down the 130 amp externally regulated unit (also shutting off the rpm reading on that engine). So I abandoned that architecture and have the 130 unit on the house bank and the 65 on the starts. I'd like to put another 130 on the second engine and combine the output to the house bank, or alternatively, run the genset to add the battery charger to the existing 130's output into the house bank. How do I implement this while still keeping the engine rpm output signal alive?

Rufus
Use a Balmar 612 or 614 to regulate both alternators.

Connect output to your house bank. Add a Blue Seas ACR to connect the start bats into the charge circuit.

Rufus said:

I'm using an externally regulated Ample Power small frame 130 amp marine unit on one engine because a large case Balmar unit wouldn't fit. But I have a related question... I attempted to dump the output of the 65 amp alternator on the second engine into the house bank and then add a Blue Sea device to dribble power into the start bank...or maybe it was the other way around. Anyway, the old internally regulated alternator kept blocking/shutting down the 130 amp externally regulated unit (also shutting off the rpm reading on that engine). So I abandoned that architecture and have the 130 unit on the house bank and the 65 on the starts. I'd like to put another 130 on the second engine and combine the output to the house bank, or alternatively, run the genset to add the battery charger to the existing 130's output into the house bank. How do I implement this while still keeping the engine rpm output signal alive?

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I had the same tech issue when my alternators cycled off on high temp. I fixed the tech issue by switching to magnetic pickups and taking the alternators out of the circuit. My engines are 6BT Cummins.

fryedaze said:

I had the same tech issue when my alternators cycled off on high temp. I fixed the tech issue by switching to magnetic pickups and taking the alternators out of the circuit. My engines are 6BT Cummins.

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Thanks, Gents. I'll check out the dual Balmar regulator mentioned above but am also interested in magnetic pickups. Where to purchase them and if they're easy to wire into the tach circuits. I'm sure they'd be more accurate than the signals off the alternators.

I use a 612 dual to control a 250A and 140A alternator on the same engine. Yep, overkill. The 140 is disabled. The 250A does a splendid job on my 1150AH AGM bank. Usually floating in about 4 hrs on a typical run. That's starting off about 350AH down. The big frame has an 8 rib serpentine pulley, it can crank at nearly full field for hours and not get over about 95C.



I'd make sure you have temp monitoring on the alternator, I have a 250cfm blower that blows outdoor ambient air into the rear of the alternators & the battery enclosure. They create a whole bunch of heat at that amperage, anticipate that you may have to handle it. My ER runs hot anyway, so I need to deal with it or I can see ER temps in the 140F range.


Love that big alternator!!

I'm pre-planning for a round trip on Trent-Severn/Rideau canals to Ottawa in 2020. My lead acid house bank is only 660 amps. Maybe the 130A alternator is enough??? The only significant load is the fridge....maybe the auto pilot...the occasional flush. Lots of time at low rpm, though... I can run the genset when off grid, although would prefer not to. Hmmm.

Greetings,
Mr. R. I don't know about the T/S lock stations but most, if not all the Rideau Canal locks stations have 30a power for rent. I think it's <$10 per night. Hope this helps.

Thanks. Yes, that does help. I think I better do some reading before I reconfigure the boat for a transatlantic crossing....

Rufus said:

I'm pre-planning for a round trip on Trent-Severn/Rideau canals to Ottawa in 2020. My lead acid house bank is only 660 amps. Maybe the 130A alternator is enough??? The only significant load is the fridge....maybe the auto pilot...the occasional flush. Lots of time at low rpm, though... I can run the genset when off grid, although would prefer not to. Hmmm.

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This topic could lead to a long and tortuous debate, along the lines of twins v singles or which anchor is best!

By lead acid, I assume that you mean flooded wet cells? My understanding is that these batteries have a lower charge acceptance rate than AGM's (also lead acid in type). I am guessing that your existing alternators, through a Balmar 612, would give a reasonable CAR for your size bank, which would not be able to take much more. The other factors are: 1. temperature of the alternators - they can't produce anything like max output when hot, and their cooling may be poor. 2. Time required to get to 100% SOC. CAR drops off a lot once you get somewhere around 90% SOC. You need the hours to get the last bit in, which is important for optimum battery life.

If your engine is going to be doing low rpm, but for long periods of time then look at the pulley size on your alternators. You may be able to get the alts to spin faster (and produce more amps) at lower engine rpm, without exceeding their limit at engine WOT.

It sounds like your bank size is suitable for your needs, you just need to tweak the charging to match your average daily engine run time.

Thanks, Brian. I'm maxed out for battery space, so that's a given. They're flooded lead acid. I'm less concerned after reading RT Firefly's note about charging stations at the overnight tie up points at the locks for at least one of the canals...maybe both. But if I can make some changes to the charging side at moderate cost, I'll do it as a backup.

Looking at the Balmar site after your earlier suggestion regarding the 612, I ran across an item called the Center Fielder, which sounds something like the model 612. Not clear as to differences, but I wonder if either of them would adequately control the "dumb" internally regulated Delco alternator, or even be compatible with the Xantrex smart regulator presently on the 130 amp unit. If I have to purchase new Balmar regulators plus a 612 (or Center fielder) device, the cost gets fairly high for this one time excursion into the canal system. If a 612 completely replaces both the dumb regulator and the existing smart regulator (makes both alternators "smart"), then I'll go that route.

The dual belt alternator pulleys are about as small as possible without running into a problem with belt slippage at high loads (not this scenario), but I'll look at alternator RPM and output at speed for 6-7 knots in the canals. It won't be very good, which is why I was thinking about a second larger output alternator to replace the dumb 65A....two midsize units running at the low end of their output curve. Good point about cooling the units, although again, they won't be running at high output. I do have a Blue Sea ACR from my ill fated earlier attempt at upgrading the charging side.

Thanks again. Food for thought.

Rufus said:

I'm pre-planning for a round trip on Trent-Severn/Rideau canals to Ottawa in 2020. My lead acid house bank is only 660 amps. Maybe the 130A alternator is enough??? The only significant load is the fridge....maybe the auto pilot...the occasional flush. Lots of time at low rpm, though... I can run the genset when off grid, although would prefer not to. Hmmm.

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130 amps should be fine. I have a hiccup in my charging system currently and have to rely on the 75 amp primary alternator to charge the 900 amp house bank. It gets it done but takes most of the day.

Ted

Desired amperage output can also on the battery manufacturer recommendations. Lifeline want you to go hard on the bulk phase and then taper off. Cat alternators can be pretty robust. Have you looked at upgrading them and then using external regulation. Some setups use one for the house bank and one for the two start banks or others straight to the house bank with a Centerfielder and ACRs.

Thanks, Ted. I tried to get a power curve for the 130 from Ample Power, but I think they closed up shop. I won't be near the boat for a couple of weeks, but my recollection is that the pulley ratio is about 2.5-3 to 1. At 6-7 knots in the canals, the engine rpm will be around 1200-1300...so maybe 3000 on the alternator. Most charts I've seen in my search to date show a fairly steep initial slope on the curve with at least 50% of max output by 3000 rpm (alternator). That would net maybe 65A from the 130A unit on the house bank. If so, that should as you say, be adequate. I guess I could shut the second engine down to up the rpm on the house bank engine if the ice cream starts to melt...another "benefit" of twins??...

Paul, the battery banks are already reconfigured to separate the house and start banks with dedicated alternators. To date it's worked fine with the 130 (house) and 65 amp (start) alternators , but I normally run the boat at least 8.5 knots where the engine/alternator rpm is high enough to squeeze adequate juice from the 130 charging unit. This little side trip illustrates a potential drawback of operating a twin originally designed to operate above hull speed at trawler crawl. A larger drive pulley on the crankshaft would be a "simple" solution, but I'm not so sure finding and fitting one is all that simple.

Thanks, everyone for the input.

If you are ever near Stuart Florida and want to upgrade your Cat Alternators go to Vic’s DC. He has heaps of alternators and parts and stocks all the bits to convert them to external regulation including the Balmar fittings.

Regards

Paul

Rufus said:

Thanks, Ted. I tried to get a power curve for the 130 from Ample Power, but I think they closed up shop. I won't be near the boat for a couple of weeks, but my recollection is that the pulley ratio is about 2.5-3 to 1. At 6-7 knots in the canals, the engine rpm will be around 1200-1300...so maybe 3000 on the alternator. Most charts I've seen in my search to date show a fairly steep initial slope on the curve with at least 50% of max output by 3000 rpm (alternator). That would net maybe 65A from the 130A unit on the house bank. If so, that should as you say, be adequate. I guess I could shut the second engine down to up the rpm on the house bank engine if the ice cream starts to melt...another "benefit" of twins??...

Thanks, everyone for the input.

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Couple of things:

You can take the alternator to a GOOD repair shop (one that actually rebuilds them) and have them test it for amperage output at a specific RPM. They have a test bench where they can load test them for a specific RPM.

Depending on the maximum engine RPM, it may make sense to change the alternator pulley to increase its RPM for the same engine RPM. Again, a good repair shop is an invaluable asset when it comes to improving the performance of your alternator.

Ted