Highest Output Alternator

[Maine Sail]

Originally Posted by Fuss

Bit of thread drift but anyway....Typhoon started it....
The alternator and LIFEPO4 sizing threads are starting.

As Lifepo4 gets more into the bigger boats the alternator subject will come up more and more.

EchoTec, Electrodyne 7kw alternators with external diodes will become the alternators to replace many of the smaller models that people are using at the moment while they still have FLA.

Even the Leece Neville industrial ones won't cut it unless the output is limited.
300+A at 24v will become much more common.

You can imagine the future.
No gas on board, all electric
Battery bank easily accepting 400amps
20 mins engine run out of the anchorage
20 mins in in the evening

7500w inverter, no generator.

A 250+A per day at 24v energy contribution will run all your systems and enable you to have an all electric galley.

Thats what I would be putting in my 45+ footer if I was making one once Lifepo4 becomes just a bit more mainstream.

The main problem we face right now is space.

The boats who need LiFePO4 the most don't have:

A) Battery space for enough LA amp hours.
B) Engine room space for an Electrodyne or J180 mount alt..


This is where the hairpin wound alts, in small case formats, have a real foot hold..... The rubber meets the road on all alternators "as installed" and engine room temp plays a huge role in performance.

Any good installation will take into account engine room ventilation..

Unlike LA batteries LFP uses 80% of the capacity, easily, so the bank can be smaller and charge to full Ah capacity faster, even with just a 160-200A alt.. As it sits right now, on our boat, we can charge from 20% DOD to 100% SOC in 2.6 hours with just 120A and a 400Ah bank... We could get away with a much smaller LFP bank but we sometimes like to spend 4+ days with no engine noise... They also never have to get back to 100% SOC so in a half hour we can get back well over a days consumption....

I am actually in the middle of some "marine use" specific testing of a new AGM technology and the manufacturer was looking for some data points on competitors.

When charging at .4C (40A on a 100Ah bank or 160A on a 400Ah bank) a well known "high acceptance" AGM goes from 50% SOC to 71% SOC where it then hits target absorption voltage. That is only 21% of the banks capacity spent in bulk charging when charging at .4C.

Arguably most boats don't have the capability of .4C charging but if cycling these AGM's to 50% DOD then bulk charging at .4C then you are hitting current limiting at about 71% SOC and spending the remaining 29% of capacity with a diminishing CAR......

This was the synopsis I sent on just the other day:

I charged the battery to .6% CAR at 14.3V (adjusted down from 14.4V at 85% SOC due to battery temp).

Battery was discharged at the 20 hour rate to 50.4% SOC (I got impatient and did not want to wait out the last 0.4%). I then fed it 0.4C charge current and tracked temp, current and voltage.

Data Points:

50.4% SOC - 74F - 32A

58% SOC - 74F - 13.40V - 32A
61% SOC -74.3F - 13.55V - 32A
64% SOC - 74.5F - 13.76 - 32A
68% SOC - 75F - 14.09V - 32A
71.1% SOC - 75.3F - 14.41V - 31.8A (Voltage Limiting/Absorption)
78% SOC - 78F - 14.40V - 20.1A
82% SOC - 80.2F - 14.40V - 15.6A
89% SOC - 84.5F - 14.40V - 8.69A
93% SOC - 84.5F - 14.40V - 5.39A



At SOC's beyond 71% this battery, at its current state of health (new but broken in), is in absorption/voltage limiting with a .4C charge rate....

It appears the pause test from the last week made little noticeable difference with the XXXXX battery in the time from approx 50% SOC to 70% SOC.

At a .4C charge from a DOD of 50% I think it is safe to say the XXXXX AGM has a bulk capability of approx 20% of the useful capacity...

[Saltyhog]

Originally Posted by Fuss

Bit of thread drift but anyway....Typhoon started it....
The alternator and LIFEPO4 sizing threads are starting.

As Lifepo4 gets more into the bigger boats the alternator subject will come up more and more.

EchoTec, Electrodyne 7kw alternators with external diodes will become the alternators to replace many of the smaller models that people are using at the moment while they still have FLA.

Even the Leece Neville industrial ones won't cut it unless the output is limited.
300+A at 24v will become much more common.

You can imagine the future.
No gas on board, all electric
Battery bank easily accepting 400amps
20 mins engine run out of the anchorage
20 mins in in the evening

7500w inverter, no generator.

A 250+A per day at 24v energy contribution will run all your systems and enable you to have an all electric galley.

Thats what I would be putting in my 45+ footer if I was making one once Lifepo4 becomes just a bit more mainstream.

The missing piece in this vision is getting the engine power to a really big alternator. We're not gonna do this with belts off the front of the engine. Way too much wear and side loading. What we need is a bell-housing alternator capable of extracting a large portion of the engine's HP. Something along the lines of what polar power does, but fit to the main propulsion engine. An alternator that delivers 500 A at 36V, (about 24 HP) would enable the vision that Foss (and myself) has. The holy grail here will ultimately be an alternator capable of collecting a significant portion of your propulsion engine's HP and converting that HP to electrical power to charge a LFP bank. Most of the pieces are available, but we need that (really) big alternator, and a way to reliably connect it to the engine.

[Sea Frog]

When choosing alternators for my future boat, I came across American Power Systems alternators. 55i outputs 300A at 28V - but it is 3 grands each, yeah...

Their 55BR-500-28J outputs even more - 500 amps at 24 volts.

[Maine Sail]

Originally Posted by Saltyhog

The missing piece in this vision is getting the engine power to a really big alternator. We're not gonna do this with belts off the front of the engine. Way too much wear and side loading. What we need is a bell-housing alternator capable of extracting a large portion of the engine's HP. Something along the lines of what polar power does, but fit to the main propulsion engine. An alternator that delivers 500 A at 36V, (about 24 HP) would enable the vision that Foss (and myself) has. The holy grail here will ultimately be an alternator capable of collecting a significant portion of your propulsion engine's HP and converting that HP to electrical power to charge a LFP bank. Most of the pieces are available, but we need that (really) big alternator, and a way to reliably connect it to the engine.

Let's not get too carried away. Even LFP has an optimum charge current. Both CALB and Winston recommend below 0.5C as optimum or "best" as the Chinese like to say. They normally advise .3C to .5C.....

0.5C on a 400Ah bank is 200A and a 400Ah bank of LFP is comparable to a 900Ah lead bank in terms of actual usable capacity when out cruising........

[a64pilot]

So, build us that turn key LFP system, and a great many of us will beat a path to your door

[Saltyhog]

Originally Posted by Maine Sail

Let's not get too carried away. Even LFP has an optimum charge current. Both CALB and Winston recommend below 0.5C as optimum or "best" as the Chinese like to say. They normally advise .3C to .5C.....

0.5C on a 400Ah bank is 200A and a 400Ah bank of LFP is comparable to a 900Ah lead bank in terms of actual usable capacity when out cruising........

Do you really think the ratio is that high? (400AH of LFP to 900AH of LA). I'm not disagreeing, but I did not think it was quite that high. You would know better though as you have practical experience with them.
You're right about my getting carried away. I was speaking to Fuss's vision of an entirely electric galley. I could see pulling many AH cooking with electric. Electric hot water would be doable. With a really big bank, I think you might entertain the idea of running cabin A/C via inverter. I *am* getting carried away. But I think LFP could be the tipping point for thinking about this stuff in completely different ways. But it'll need to come down in cost first. A really big bank does not usually make sense with LA as there is no good way to charge them quickly enough, even if you do have space for it. That's much less of a problem with LFP.
To the OP, I agree with others that the AT alternators from Balmar are very good based on their specifications, curves, and especially efficiency numbers. Better efficiency means less heat generated. Mark Grasser's stuff also looks promising. Don't expect to get rated performance (for very long) from an auto alternator.

[a64pilot]

OK, maybe I'm stupid again, but assuming a large enough charging current, size of the bank is irrelevant to charging time. One battery or 100 batteries will take the same amount of time to charge.

[Ex-Calif]

Originally Posted by Saltyhog

The missing piece in this vision is getting the engine power to a really big alternator. We're not gonna do this with belts off the front of the engine. Way too much wear and side loading. What we need is a bell-housing alternator capable of extracting a large portion of the engine's HP. Something along the lines of what polar power does, but fit to the main propulsion engine. An alternator that delivers 500 A at 36V, (about 24 HP) would enable the vision that Foss (and myself) has. The holy grail here will ultimately be an alternator capable of collecting a significant portion of your propulsion engine's HP and converting that HP to electrical power to charge a LFP bank. Most of the pieces are available, but we need that (really) big alternator, and a way to reliably connect it to the engine.

Maybe one of the "smart" alternator companies will look at a starter/generator either purpose built or an adaptation of some kind.

Power take off gearboxes?

Problem is the market is so darn small and the number of different engine types makes this a non-profit operation...

It will be interesting to watch this develop.

[a64pilot]

Assuming 50% availability of a lead acid battery bank, a 900 AH bank gives you 450 useable AH.
Assuming 80% availability of an LFP bank, then you have to have 562 AH bank to get 450 useable, or am I not understanding something?

50 amps will run a 5,000 BTU Marine AC, so if you had 450 available, assuming 100% efficiency conversion just to keep the math simple, then you could run the AC at 100% duty cycle for 9 hours. Of course inverters are not 100% efficient and most likely your AC won't run continuously either, but I think AC is doable. I'd like a KW of available though

[a64pilot]

Originally Posted by Ex-Calif

Maybe one of the "smart" alternator companies will look at a starter/generator either purpose built or an adaptation of some kind.



Power take off gearboxes?



Problem is the market is so darn small and the number of different engine types makes this a non-profit operation...



It will be interesting to watch this develop.

The starter/ generator we put on PT6 engines is either 250 or 300 amps at 28V at 100% duty cycle, that's 500 or 600 at 14V.
They can easily start a Diesel too, to start a Garrett engine, you have to turn everything including the prop as a Garrett is not a free turbine, the starter will pull 1000 amps at 28V starting a Garrett.
It's theoretically possible, but as a retrofit? Be hard to do.
Full circle, we have built us a Hybrid haven't we A big battery bank for any use, a generator to charge it, and may as well go for an electric motor to drive the boat either from the bank, the generator or both if you really need a surge of power

[Ex-Calif]

Originally Posted by a64pilot

The starter/ generator we put on PT6 engines is either 250 or 300 amps at 28V at 100% duty cycle, that's 500 or 600 at 14V.
They can easily start a Diesel too, to start a Garrett engine, you have to turn everything including the prop as a Garrett is not a free turbine, the starter will pull 1000 amps at 28V starting a Garrett.
It's theoretically possible, but as a retrofit? Be hard to do.
Full circle, we have built us a Hybrid haven't we A big battery bank for any use, a generator to charge it, and may as well go for an electric motor to drive the boat either from the bank, the generator or both if you really need a surge of power

Yeah - I was thinking along the lines of aviation starter gens.

I think hybrid is sort of the logical direction once you get all this battery power on board.

When you run the hydrocarbon engine you want it up on the power curve at all times.

Whether that engine is producing electricity for charging or electricity to drive a motor spinning a prop the generating system now becomes the heart of the system not the diesel.

Simplicity & flexibility might say a stand alone diesel/generator (pick your kva) and a separate electric boat motor with the battery bank as the reservoir.

The electric boat guys are working on this hard but many of them are too focused on the "green" aspects and wanting to propel the boat with the engine off.

But this is not an electric boat thread so I will go back to lurking...

[Maine Sail]

Originally Posted by a64pilot

Assuming 50% availability of a lead acid battery bank, a 900 AH bank gives you 450 useable AH.
Assuming 80% availability of an LFP bank, then you have to have 562 AH bank to get 450 useable, or am I not understanding something?

50 amps will run a 5,000 BTU Marine AC, so if you had 450 available, assuming 100% efficiency conversion just to keep the math simple, then you could run the AC at 100% duty cycle for 9 hours. Of course inverters are not 100% efficient and most likely your AC won't run continuously either, but I think AC is doable. I'd like a KW of available though

Yes from a full charge you would have 50% of the bank to utilize. However the problem, when cruising, is that it becomes extremely difficult to push back much above 80-85% SOC due to declining charge acceptance making it so slow and extremely inefficient. Most cruisers wind up cycling between 50% and 80-85% (often called "The Cruiser "Rule") because getting back to 100% with lead acid is like walking up hill on ice. The reality, when away from the dock, is that actual usable capacity of most lead acid banks is about 30-35% (bulk plus a little bit of acceptance taper) except for those times when you trudge through a push to 100% for the health of the batteries.. With LFP the taper is extremely short so getting back to 100% is very easily done thus utilizing 80% of the bank on a regular basis is cake walk where with lead acid it is not and you really need to size the bank for about 35% usable capacity.

[a64pilot]

Got it, I had forgotten that last 15% took forever to get. I guess a logical use would be to use the Diesel and Alt until the bulk phase was over, then shut down and try to "top off" the battery with Solar?
You think a LFP BMS is close? I'm used to LI-PO and without a BMS, your playing with fire, literally.

[sy_gilana]

I am sure someone is going to knock up a BMS using an Arduino board soon. I would use a PLC to make my own BMS.

Back to the OP's question, no need to go the Balmar route, most brushless alternators are "high output" Most city busses and all tourist long haul busses have these, there are huge electrical loads, nevermind firetrucks and ambulances, they use this type...
http://www.dixie-electric.com/_dixie...0-DELA-180.pdf

[Ex-Calif]

Originally Posted by a64pilot

Got it, I had forgotten that last 15% took forever to get. I guess a logical use would be to use the Diesel and Alt until the bulk phase was over, then shut down and try to "top off" the battery with Solar?
You think a LFP BMS is close? I'm used to LI-PO and without a BMS, your playing with fire, literally.

I think that's how most cruisers interpret what is happening. Run the engine for bulk and then solar/wind does the rest over the next 5-6 hours...

The reality is unless all this is sized right the daily consumption means a lot of that solar is used up running the boat all day and not much left for absorption and float...

I am glad the sparkys are working this and blazing a trail. This guys will figure out how to make it work and the manufacturers will (eventually) start making stuff that can come off the shelf for the rest of us.

Some day there will be a conversion kit for $5000 + batteries, some time after that the prices will come down...

Right now reading the LiFePo4 threads for me is like a pig looking at a wristwatch...