Alternator choices

[john61ct]

Originally Posted by Frankly

has me thinking about bringing some cooler air from the bilge to the alt.

exhaust the hot air, where the replacement cooler air comes from doesn't matter.

Ideally would help with cabin ventilation in hot weather?

[evm1024]

One of the reasons that I was looking at the CS144 alt is that there are many parts available for it.

For example here is a replacement 200 amp stator for $80.

Something that this thread could be useful for is if we come up with a list of alternators and the real world full time output we could expect from them.

Of course this will beg the question of the cooling air temp and the delta T for the unit that we would allow.

[john61ct]

Originally Posted by a64pilot

I think an 80 amp alternator may be able to make close to rated power, a 165 about half or 80 ish, and what I’d like to know is what is a 200 capable of?

It all depends on the temperature.

The higher the (potential) output the more heat is an issue, as long as you stay with the small frame, which is **inherently bad** at shedding heat unless in Arctic conditions.

Taking the rectifier / diodes off the body helps, but only to a point.

> It’s really the LFP crowd that would get the most benefit out of a monster alternator, most of use lead acid guys not as much.

An 800AH AGMs bank 50% depleted would benefit, get up to 85-90% **much** faster. But the remaining 5-6 hours to get to 100% is another story.

> Now I think I understand why

And that's always A Good Thing.

Make sure to send as much business to that guy as you can, so rare in a salesperson these days, should get rewarded.

[john61ct]

Originally Posted by Pizzazz

400 AHr battery bank which in turn cannot (or should not) take much more than 100A charging current) and that is only for a brief period of time before you hit absorption.

Yes, but some bank types are capable of accepting .8C or more in bulk, LFP well over 1C all the way to Full.

And running a 30gph watermaker while charging the bank sounds good to me, maybe even aircon for some, or as you said cooking without flammables in the cabin.

[a64pilot]

Originally Posted by evm1024

Some people do have an obsession with high output alternators. Not me... And with respect neither your or my understanding of others desires, needs or obsessions matters.



In my case I have 700 AH of LiFePO4 in the house bank which can accept much more charge than I can throw at it (or want to throw at it).



If I were to use 200 AH/day then I would need to run a 100 amp alternator for 2 hours each day (assuming that I could actually get 100 amps out of it). Skip a day and we are up to 4 hours.



But with a 200 (real amps) amp alternator it is only 1 hour per day.



Still too much which is why Dog invented solar.

I’m going to go out on a limb here and assume you meant God, and autocorrect changed it to Dog?
It’s happened to me too

I’m thinking that about 100 amps is about all you can get out of a small frame alt, but you know that is not bad at all. That is about 1.4 KW.
If I had a bank that could accept megawatts, I think I would have to find a way to make a large frame fit, or just do with Solar or a generator.
One day, maybe I will have LFP and my only concern will b emailing enough power to recharge, and not have to worry that it will take 5+ hours.

[john61ct]

Originally Posted by evm1024

CV is "easy" to understand. Our supply (charger, alternator, solar, etc) adjusts the supply of current as it monitors the voltage and then stops supplying more current when a set voltage is reached. The voltage is fixed and the current varies.

yes but to nit pick 8-)

The bank chemistry's SoC / resistance is what regulates current variation if any. The source is just putting out the maximum it can (is set at), or what the bank accepts, whichever is lower.

That is true for both Bulk/CC and Absorb/CV, the only difference being that charge regulation is doing its job of not allowing V to climb past the setpoint.

From the "user's" black box POV, that's all they need to understand afaic about how regulation works and the role of resistance

[john61ct]

Originally Posted by evm1024

And I think that a school bus type alt is overkill and over budget.

Can be found quite cheaply, well under $300

Even my fantasy alt, 500+A continuous duty @24V can be found for under $500, in my case 20 minutes away for $350.

But horses very quickly becomes the limiting factor, that last needs 30HP just for itself, never mind propulsion.

Which is why a field current kill switch at the helm quickly becomes A Good Idea.

[john61ct]

Originally Posted by a64pilot

not have to worry that it will take 5+ hours.

Yes with LFP my ideal design goal would be max 4 hours per week at high idle, and hopefully concurrently making water.

No need for a separate genny, for me.

[john61ct]

Originally Posted by evm1024

Something that this thread could be useful for is if we come up with a list of alternators and the real world full time output we could expect from them.

Best you could say even with large frames, is with an MC-614 and "in cool conditions".

The temp issue is so variable, throws all predictability out the window until **your** setup is out motoring in **those** real life conditions.

[a64pilot]

You may need higher than high idle for alternator cooling.
Then running s BIG alternator when your motoring becomes s real issue, cause it’s the same as being way overpropped, you would be lugging the motor, so some happy medium will be need to be reached.

Excepting it’s size, a school bus / ambulance alternator makes better sense to me for a DIY guy, way cheaper and capable of way more realistic power than a souped up high dollar small frame alt.
Just not mainstream available at the local Marine store.

[evm1024]

Originally Posted by a64pilot

You may need higher than high idle for alternator cooling.
Then running s BIG alternator when your motoring becomes s real issue, cause it’s the same as being way overpropped, you would be lugging the motor, so some happy medium will be need to be reached.

Excepting it’s size, a school bus / ambulance alternator makes better sense to me for a DIY guy, way cheaper and capable of way more realistic power than a souped up high dollar small frame alt.
Just not mainstream available at the local Marine store.

I highlighted one of the things that worry me.

I could choose something in a J180 mount like the Delco 28SI (28SI 12V 200 amp 1-wire J180 mount 20 lbs). You can find them for $150 and up.

I have a Perkins 4.236 with a 2" mount so I would need to convert to the J180 mount. Also I would want to make sure that the 20 pounds would hang off the engine well. As it is I'm not planning to mount an alternator on its own pad off the engine.

Some new CS144 are going for $100 and 200 amp kits are another $100. Plus they and parts are everywhere. Was there ever a Balmar or other marine alt place that used the CS144 as its base?


Still food for thought.

[wayne.b]

Originally Posted by evm1024

I'm tempted to head to a junkyard and pull a CS144 out of a wreak just to see how well it would fit on the engine. A used alternator would give me a chance to see what was involved in converting the CS144 to external regulation and a chance to rebuild one.

Anybody using a CS144? Are you using external regulation (whos conversion parts), How about external rectifiers?

Regards!

===


I've been running a CS144 with dual belts on my stbd engine for many years. As you pointed out, they are a good value for the money, easily repairable just about anywhere, and cheap enough that you can carry a spare or two. That said, if you are going to use it to charge a large house bank you will need to beef it up with a smart external regulator that monitors alternator temperature and limits charge current to a safe level. Also, the most you can expect from a single belt is about 100 amps unless it is one of the wide serpentine types. My 1,000 amp-hour house bank is charged by the port side engine which has a 320 amp fire truck alternator on a custom J-180 mount, and driven by 3 belts. As big as it is, I've still needed to take steps to limit continuous output to less than 200 amps.

These guys are a good source for CS144s, parts and tips. They can build them for external diodes, and I'm sure they could also customize one for external regulation. I'm not doing it on mine but would if I were using it to charge the house bank.

https://alternatorparts.com/extreme-...-144-type.html

[evm1024]

Originally Posted by wayne.b

===


I've been running a CS144 with dual belts on my stbd engine for many years. As you pointed out, they are a good value for the money, easily repairable just about anywhere, and cheap enough that you can carry a spare or two. That said, if you are going to use it to charge a large house bank you will need to beef it up with a smart external regulator that monitors alternator temperature and limits charge current to a safe level. Also, the most you can expect from a single belt is about 100 amps unless it is one of the wide serpentine types. My 1,000 amp-hour house bank is charged by the port side engine which has a 320 amp fire truck alternator on a custom J-180 mount, and driven by 3 belts. As big as it is, I've still needed to take steps to limit continuous output to less than 200 amps.

These guys are a good source for CS144s, parts and tips. They can build them for external diodes, and I'm sure they could also customize one for external regulation. I'm not doing on mine but would if I were using it to charge the house bank.

https://alternatorparts.com/extreme-...-144-type.html

Thanks for the good info. I am currently running a serpentine belt on my engine. K6 as it is.

I have been looking over the alternatorparts.com website for a while. A good source for any who are interested.

I do have a MC-612 regulator and will be playing with one of the 3a versions of the VSR arduino regulators....

[Frankly]

"exhaust the hot air, where the replacement cooler air comes from doesn't matter."

IP 32 comes with a 3" Rule exhaust blower, but it is at the rear end of the motor box and so are the air inlet areas.

I have 600 AH house bank and consume 100 to 125 AH a day. I can sit 3 days without any charging but then putting 100 or so back is a real load not 30 minutes and then into acceptance. That 100 A Balmar putting out 80 amps will hit 200 F in less than 30 minutes under those conditions. The 3GM is running 165 F so just a hot well insulated environment. When I slid the motor cover fwd, the alt temp starts counting down like the fuse timer in a James Bond Movie.

[john61ct]

Originally Posted by a64pilot

You may need higher than high idle for alternator cooling.

Yes, hoping supplemental active air exchange will help, I really prefer the lower rpm vibes.

There are purpose-built alts designed to put out 200+AH all day long at only 1800, rock solid build quality, great support, but pricey.

> Then running s BIG alternator when your motoring becomes s real issue, cause it’s the same as being way overpropped, you would be lugging the motor, so some happy medium will be need to be reached.

MC-614 de-rating for the win. Not sure if directly scaling back field current "live" from the helm works, that is reduces current while maintaining setpoint V


> Excepting it’s size, a school bus / ambulance alternator makes better sense to me for a DIY guy, way cheaper and capable of way more realistic power than a souped up high dollar small frame alt.

Yes I agree, small frame to me only makes sense if 80-100A actual output is enough, or you just can't mod for a bigger one.