Tiny Powered Alternators & DC Generators

[newhaul]

Originally Posted by Dockhead

If you like technology, I would suggest looking more at the motor and less at the alternator -- the motor is the big problem for small, quiet, efficient generators for yachts. A more efficient alternator would be great, but that's just an incremental improvement to a device which already works pretty well and is cheap and reliable.



I think a Stirling engine is vastly better than diesel for this application, almost silent and vibration free, up to 50% thermal efficiency, simple, cheap. There was a NZ company making Stirling engine powered small generators for yachts (WhisperGen), but the factor was destroyed by an earthquake a few years ago.


You might be able to find a used one.


For diesel power, you don't have any good choices, if you want something light and compact. Everything available is either very heavy, or noisy and light duty. There is no way to run a one-lunger diesel at 3000 RPM in a small boat and live a normal life, no matter how many sound enclosures you have. The two cylinder is hardly better. Diesel generators start to get more or less tolerable only in low speed, three cylinder versions, and these are too big and heavy for small boats. Mine weighs about 600 pounds IIRC.


There is a big gap in the market for a really quiet non-petrol burning generator capable of maybe 2kW.



A somewhat reasonable compromise are the "mid speed" NexGen generators made in Florida. They are pretty compact and reasonably priced, but not that quiet, and the one-lunger Kubota roto-tiller engines are not made for intensive use.



The Honda and Yamaha suitcase generators are fine for what they are, but you can't run or keep them inside the hull volume -- where will you put it? Nor are they that quiet when they are loaded up.




If you can fit a decent amount of solar without killing sailing performance with windage (or if you don't care about sailing performance), then forget about generators.

then there is my air cooled 4k diesel unit based on a yanmar . It will live on the lazzerette in its own weather enclosure. ( hope to not need it but glad I have it)

https://www.yanmar.com/us/product/ydg3700/

Mine doesn't look this good.

[Dockhead]

Originally Posted by newhaul

then there is my air cooled 4k diesel unit based on a yanmar . It will live on the lazzerette in its own weather enclosure. ( hope to not need it but glad I have it)

https://www.yanmar.com/us/product/ydg3700/

Mine doesn't look this good.

85dB -- yowza! Please don't run it near me!

[newhaul]

Originally Posted by Dockhead

85dB -- yowza! Please don't run it near me!

one of the main reasons I hope to not need it . Looking to add a better muffler/ silencer on it under water exhausting is a possibility after all its diesel

[newhaul]

Originally Posted by Dockhead

85dB -- yowza! Please don't run it near me!

it was also free because it needed a $20 injection pump.
They didn't want to fix it.

[Dockhead]

Originally Posted by newhaul

it was also free because it needed a $20 injection pump.
They didn't want to fix it.

Free is good!

[newhaul]

Originally Posted by Dockhead

Free is good!

now I have the counter weight to my new anchor and chain.

[rgleason]

Couldn't agree more Dockhead. We made a choice in 2013 to install 3ym30 at beginning of summer sail season when the westerbeke failed. Sean advised that we missed an opportunity. Now my choice is to get a better alternator to drop the rpm down and reduce heat and eng noise.
Our boat is too small to have too much stuff on it. We like to sail thats why we have the boat. Dockhead, you're right there will be windage. There seems to be grab rails, hatches, mast, running rigging etc all over with no big deck area for solar, so the bimini location appeals as a solution.

[newhaul]

Originally Posted by rgleason

Couldn't agree more Dockhead. We made a choice in 2013 to install 3ym30 at beginning of summer sail season when the westerbeke failed. Sean advised that we missed an opportunity. Now my choice is to get a better alternator to drop the rpm down and reduce heat and eng noise.
Our boat is too small to have too much stuff on it. We like to sail thats why we have the boat. Dockhead, you're right there will be windage. There seems to be grab rails, hatches, mast, running rigging etc all over with no big deck area for solar, so the bimini location appeals as a solution.

with a bimini 400watts solar is easily within reach on your bristol.

[rgleason]

Yes, will do in 2 steps.

[newhaul]

Just stumbled on this belt driven generator
https://www.ebay.com/itm/New-CE-NIEH...&ul_noapp=true

Or this one for smaller systems
Should work with a 4 HP motor easily
https://www.ebay.com/itm/Powermaster...&ul_noapp=true

[newhaul]

And a diesel engine to run it
https://portablegenerator.en.made-in...el-Engine.html

[wallythacker]

Originally Posted by john61ct

I have never seen a diesel small enough to carry around, isn't heavy weight even at small HP inherent in the technology?

https://www.stevewebb.co.uk/index.ph...D&area=Engines

There are more diesels of varying power on the site.

[john61ct]

Originally Posted by newhaul

And a diesel engine to run it
https://portablegenerator.en.made-in...el-Engine.html

To run what?

At say one HP per 280-320W output, I think 30-35HP would be required to spin that 400A unit into an LFP bank.

If from the main engine, also add what's needed for cruising propulsion, or set it up so you can choose between, efficient at both.

[john61ct]

Originally Posted by wallythacker

https://www.stevewebb.co.uk/index.ph...D&area=Engines

There are more diesels of varying power on the site.

For me, I would want

just using OTS standard diesel

Not "36% paraffin and 36% ether and 25% castor oil and with a 2 to 3 % splash of Amyl Nitrate"

Technology known to mechanics in primitive locations.

Easy parts availability in remote locations.

Also thousands of hours between overhauls.

[newhaul]

Originally Posted by john61ct

To run what?

At say one HP per 280-320W output, I think 30-35HP would be required to spin that 400A unit into an LFP bank.

If from the main engine, also add what's needed for cruising propulsion, or set it up so you can choose between, efficient at both.

you really should read my postings .
Like the one right above the one you quoted.
The engine would run the 90 amp generator I linked to
https://www.ebay.com/itm/Powermaster...&ul_noapp=true