Highest Output Alternator

[S/V Alchemy]

Originally Posted by Panope

Does anybody just add a second, cheap normal alternator (on a separate belt opposite the other alternator) if they want more capacity?

Seems like it could eliminate a few problems such as side loading of the crank bearing. One would also have redundancy.


Steve

Yes. It's called dual or double power take-off and the side loading is in some sense mitigated because it's distributed between three or more points of contact (if you have an idler pulley, for instance) and you are in theory running smaller individual alternators (cooler, too) that yet may have a greater output than a single alternator. The output of each alternator can be directed (start or house or watermaker) or combined to provide more amps at the desired voltage set-point. All of which means nothing if you don't have the horsepower left over to push the boat, or your banks' ability to accept a whopping great charge is in question.

Or so I understand and so I have planned out. If I'm wrong and my results seem weird, I'll post that here too in honour of guys like btrayfors and Maine Sail who have been my mentors on the topic of making amps on boats.

[Dockhead]

Originally Posted by botanybay

Sounds like almost exactly what I am looking to do for my system. I currently have 440 amp/hours x 24v for the house bank. The standard alternator which came with the engine is a 35amp x 24v alternator with a single 3/8 inch belt. It has not been a problem as I can charge at 150 amps x 24v off the generator using the inverter (I limit the inverter to 100 amps and there are almost always other loads so I don't see over 0.2C) but the charger is capable of 200 amps @ 24v.

What I am interested in is the belt configuration you are running. My engine is a Perkins M90 (basically a 4-236) which is a slow turner (nominal cruise is 1700 - 1800 RPM.

Double v-belts, nothing fancy. It works ok, although I have to replace them fairly often and keep an eye on the belt tension. I would think a toothed belt of some kind, or serpentine, would be better.

[Hud3]

When I had a 210 A Balmar installed on my Yanmar 4JH3B-E I checked with Mastry Engines (the Yanmar dealer that supplied the engine to Island Packet Yachts) to make sure the side load would be acceptable. I also bought the double sheave pulley from them and installed it on the flywheel. I used Dayco Top Cog V-belts, which seemed to hold up very well.

[darylat8750]

Originally Posted by SV THIRD DAY

From someone who makes a living answering cruisers technical emails, let me divert this thread a little further and say this about technical questions and answers. In about 30-40% (possible more on Fridays and even up to 65% during a full moon) of the questions I'm asked I know half way into the question that they are asking the wrong question. It's not because I'm smarter than they are, it's just because in doing something for a living, you get the same questions literally hundreds and hundreds of times and you then start to learn where the question is coming from, where it is going and how best to answer it so that it doesn’t lead to another question.

Not to pick on you JoeFish, but since the 99% of us didn’t live up to your standards for internet advice and attention span, lets review.



No mention of the most important issues in your question: Size of batter bank, type of battery bank, LiOn is a game changer and no we have no idea of the alt size range you are looking for. So we guess a little at first on just want you are asking for. Do you know that you will need more than a 1/2" V-belt for an alternator above 100A? heck...we don't know what you know or don't know???



Got it now, you are converting to cutting edge marine technology but at the same time make a comment about not understanding the general basics of how alternators work vs load and Hp. So right away all of us are thinking along these lines: does he know the basics or do we back up and do a battery charging and alternator school 101 series webinar for free for him? Do we risk giving technical info without a background basic understanding and then cause him more problems with a technical questions he doesn't understand? This is a huge risk in giving someone that doesn'tunderstand something 3/4 of the technical informaiton when the other 1/4 can cause a fire with their LiOn batteries!

[ Rich is one of the sharper guys in these discussions and even he stumbled between LiFePo an LiOn and the fire issue with LiOn. Typo I hope. ]

Well how would WE know what you consider HO our not? Work with us here….



Mainsail has a great way of cutting through the crap, fog, ½ questions and misdirections asked by clients and free info seekers on the web. If you have spent any time on the LiOn threads where people try to literally kick his ass and question his manhood for not giving them the answer THEY WANT but rather giving them the answers THEY NEED you would understand a bit that MainSail easily qualifies for Internet Free Advice Sainthood. The great thing about internet chat room Q&A is that you are absolutely going to get responses from people who approach not just the answer but your very question from a totally different point of view. Is this a racing boat, a cruising boat, do you anchor more than motor around? Will you have a generator and not even need the alternator on the engine anway? ****...all of that info goes into being able to give you the best answer regardless of what question you asked. If you ask the wrong question, you get the wrong answer. Some like the diversity of thought and answering styles and can wade through the tall grass…others think the guy screaming grass fire on the Serengeti isn’t paying attention.

Check brackets above. I'm iPad challenged.

[lmantuano]

G'day!

Hope it's ok asking a question in this thread..

helping a friend installing his new ElectroMaax 120Amp small frame HO alternator with dual Vee pulley replacing crappy OEM 75Amp on a Vetus (Mitsubishi) 3-cyl 28HP, charging crank battery and 330AH AGM house bank..

The alt arrived, friend did all the mechanical stuff and I proceeded with the electrics.

All done, started the motor, no output from alt.. few choice words and, when calm prevailed, found that the local dealer had shipped an isolated-ground model, without telling us, lovely..!

Connected the alt GND post to BATT- and engine block, all good now.

Anyway, that's the story and this is the question:

Given that the Negative diode heat-sink is physically insulated from the alt case with a thin plastic/rubber insulator layer (I assume one with high thermal conductivity) and plenty of white thermal goo, how much LESS efficient at cooling the diodes is this, compared to direct contact between heat-sink and case in a proper case grounded alternator?

Should I bother removing the insulation (notwithstanding warranty issues)?

I've asked EM support, with mixed success..

TIA

lm

[ColdEH]

Originally Posted by typhoon

I direct coupled my 325 A EchoTec alternator to the crank shaft with a love joy connector.

It runs at the generators 1800 RPM and produces around 265 amps at 12 volt at that speed.

I think it takes 9 hp to spin it. Belts on a small engine were not an option as it would probably eat the bearing at the fly wheel from the side force. I guess I could have put a load belt on the opposite side but the "love joy" was a simpler solution.

Regards

Just got it all up and running last week . This is what I am getting out of my alternator at generator speeds , 1800 rpm

Regards

[rwidman]

Originally Posted by JoeFish

............. I sail on AP a lot and that tends to suck up about 50Ah a day p..............

You need to understand a little more about electricity. By definition, an amp hour (AH) is an amp of current flowing for one hour. An amp flowing for 24 hours (a day) would be 24 amp hours. Two amps flowing for 24 hours would be 48 amp hours, etc. It doesn't make sense to say "50 Ah a day".

The current consumed by your AP is the amount of current consumed by the AP multiplied by the hours used. If it draws two amps and runs eight hours, it has consumed 16 amps.

[mitiempo]

Originally Posted by rwidman

You need to understand a little more about electricity. By definition, an amp hour (AH) is an amp of current flowing for one hour. An amp flowing for 24 hours (a day) would be 24 amp hours. Two amps flowing for 24 hours would be 48 amp hours, etc. It doesn't make sense to say "50 Ah a day".

The current consumed by your AP is the amount of current consumed by the AP multiplied by the hours used. If it draws two amps and runs eight hours, it has consumed 16 amps.

You can consume 16 amps for 1 minute, 10 hours or 24 hours. AH is amps consumed x duration. AH is the correct designation. That is why batteries are rated in AH, not amps.

[SV THIRD DAY]

I somehow doubt a guy switching to LiFePO4 batteries doesn't understand the difference between Amp and AH...it makes total sense to me anyway to say that his autopilot uses 50AH per day...I don't see the problem.

Originally Posted by JoeFish

Yes, we're switching to LiFePO4 now so this is the time to get a high output alternator..

JoeFish
Spend some time on the LiFePO4 thread because the key for you going to LiFePO4 batteries won't be how big you can go...but what rated output your alternator can run at! LiFePO4 battery banks are alternator killers if you don't have proper regulation on them. The set-ups I have been using is a 160A alternator cut back with the Balmar reg to 100A. That keeps the alternator from burning up from heat.

[rwidman]

Originally Posted by SV THIRD DAY

I somehow doubt a guy switching to LiFePO4 batteries doesn't understand the difference between Amp and AH...it makes total sense to me anyway to say that his autopilot uses 50AH per day...I don't see the problem. ........

See anything wrong with the term "knots per hour"?

I think if you wand to discuss technical stuff and make any sense of it you have to understand and use the technical terms correctly.

[a64pilot]

You know why is it no one ever talks speed in miles, it's always miles per hour?
But knots is acceptable? If you don't reference a time interval, well then it's just distance isn't it?

[SV THIRD DAY]

only in an internet chat room.....

[DeepFrz]

a64pilot, knots is a term for nautical miles per hour, so knots per hr. is acceleration.

[s/v Jedi]

Okay.

[Nicholson58]

Originally Posted by JoeFish

I'm looking for a new alternator for our motor.

In a perfect world I'd like to find one that I can push a lot of amps into our house batteries quickly, as I sail on AP a lot and that tends to suck up about 50Ah a day plus all the other normal loads from radios, instruments, etc. (I'll admit we use far less in that department than some).

An suggestions for something high output?

Original engine was 16HP and we made hull speed with that. The new motor is a 26HP triple with a max prop so we have plenty of reserve to push a big alternator.

26 HP is not going to drive a huge alternator. Figure out what drag you can really tolerate. You can find the conversions for watts - HP. Remember to account for the inefficiency of the belts, alternator, engine etc. These are real numbers.

If you want to shop for inexpensive, go to a truck service & alternator re-builder. Get an alternator with an external charge controller. I use Balmar on a 2-belt 1.5 KW 24 VDC alternator. You want an external controller that can deliver the charge cycle necessary for your batteries. These will also taper off demand as your battery is charged so that you engine is not unnecessarily loaded.