Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 04-11-2017, 09:31   #1
Registered User

Join Date: Oct 2015
Posts: 474
WHAT IS A GOOD GENERATOR ??

One that has a heat exchanger and 12volt output as well as 120 volt AC ??? Approximately 4-6 KW---- Don't say MASE!
__________________

__________________
geoleo is offline   Reply With Quote
Old 04-11-2017, 10:47   #2
Registered User
 
Jman's Avatar

Join Date: Sep 2012
Location: Northeast, USA
Boat: Luders 36
Posts: 230
Re: WHAT IS A GOOD GENERATOR ??

I am by no means an expert, but pretty sure you are not going to find a marine generator that has both 120ac and 12v. Normally 120 (or 220). Battery charger used to get 12v. There are a few 12v models, then you use inverter to get to 120.
__________________

__________________
Jman is offline   Reply With Quote
Old 04-11-2017, 13:02   #3
Registered User

Join Date: Oct 2015
Posts: 474
Re: WHAT IS A GOOD GENERATOR ??

Yes I know-- but a friends trawler Northern Lights 8KW does have a 120+ a 12 volt output-besides if a gen with a alternator that can charge its own battery why cant it also charge a house bank? or is it rocket science
__________________
geoleo is offline   Reply With Quote
Old 04-11-2017, 13:19   #4
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 1,676
Re: WHAT IS A GOOD GENERATOR ??

Most generators have a 12v charging circuit intended for the generator's separate battery. The 12 volt circuit isn't intended to quickly charge large banks of semi discharged batteries, except on generators large enough have an alternator.
If you're running the generator, you have ac for your normal charger if the generator is sized correctly.
Don't buy a generator with an air cooled engine.
__________________
Lepke is offline   Reply With Quote
Old 05-11-2017, 05:13   #5
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,641
Re: WHAT IS A GOOD GENERATOR ??

If it's an AC generator, use AC power via charger or charger/inverter to charge the house bank.

As far as choice of generators goes - first decision is intermittent duty rated high speed vs continuous duty rated low speed. The latter is more expensive, heavier, and bulkier, but quieter and more reliable and longer lasting.

Then, if heavy duty, choose from leading makers - Northern Lights, Onan, Kohler. I think most people consider NL to be the best, but I can't see a lot of difference between these.

If light duty, then different choices.
__________________
"Parce que je suis heureux en mer, et peut-Ítre pour sauver mon ame. . . "
Dockhead is offline   Reply With Quote
Old 05-11-2017, 05:27   #6
Marine Service Provider

Join Date: Sep 2012
Location: Virgin Islands
Boat: 1999 Leopard 45, 45 foot cat, 1980 Hunter 33, 33 foot monohull
Posts: 405
Re: WHAT IS A GOOD GENERATOR ??

Quote:
Originally Posted by geoleo View Post
One that has a heat exchanger and 12volt output as well as 120 volt AC ??? Approximately 4-6 KW---- Don't say MASE!

I am curious by not MASE?
__________________
contrail is offline   Reply With Quote
Old 05-11-2017, 05:31   #7
Registered User

Join Date: Jan 2010
Location: Narragansett Bay
Boat: Able 50
Posts: 3,045
Re: WHAT IS A GOOD GENERATOR ??

The best generator that I ever owned was one of these.

NEXT-GEN - Marine Power Units
__________________
savoir is offline   Reply With Quote
Old 05-11-2017, 05:38   #8
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,641
Re: WHAT IS A GOOD GENERATOR ??

Quote:
Originally Posted by savoir View Post
The best generator that I ever owned was one of these.

NEXT-GEN - Marine Power Units
Those look good to me, too. Can you give details about your experience?
__________________
"Parce que je suis heureux en mer, et peut-Ítre pour sauver mon ame. . . "
Dockhead is offline   Reply With Quote
Old 05-11-2017, 06:52   #9
Registered User

Join Date: Jan 2017
Posts: 2,179
Re: WHAT IS A GOOD GENERATOR ??

I wish there were more commercially made units dedicated to just spinning large-frame high-output alternators, I have very little use for shore power.

300+ amps continuous output, even x2 for redundancy.

Pulley sizes to optimize output at lowest rpm producing enough torque when loaded.

Balmar adjustable VRs

Powerful cooling over the diodes.

Perfect into a big LFP bank, no more than 30min runtime per day.

I suppose not too hard to DIY with a good engine guy, maybe 20-25HP?

But purpose built OTS would be better.

Q: stock truck alts or speciali$ed marine ones?
__________________
john61ct is online now   Reply With Quote
Old 05-11-2017, 07:35   #10
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,641
Re: WHAT IS A GOOD GENERATOR ??

Quote:
Originally Posted by john61ct View Post
I wish there were more commercially made units dedicated to just spinning large-frame high-output alternators, I have very little use for shore power.

300+ amps continuous output, even x2 for redundancy.

Pulley sizes to optimize output at lowest rpm producing enough torque when loaded.

Balmar adjustable VRs

Powerful cooling over the diodes.

Perfect into a big LFP bank, no more than 30min runtime per day.

I suppose not too hard to DIY with a good engine guy, maybe 20-25HP?

But purpose built OTS would be better.

Q: stock truck alts or speciali$ed marine ones?
Noelex had something like this on his old boat, using a small propulsion engine (IIRC) to drive a jumbo school bus alternator.

I consider something like this for my own next boat.

I use a lot of AC power on board (comforts of home ), but I don't care whether power is generated by AC or DC, because the conversion is very efficient, first of all, and second even I don't use more AC power, than I do DC power, so I'm converting in any case.

I like this idea because a bog standard school bus alternator (there isn't any such thing as a "specialized marine alternator" AFAIK) is cheap and can be repaired by any third world auto electric shop with a screwdriver and a hammer, or by me. Or swapped out with a spare.

So easier to keep running than a regular AC generator.

The challenge, which I don't understand, is how to operate it. Maybe you just increase the revs if you think you will need more power -- you can work out max available power at different revs. Being careful not to leave it running at higher speeds with no load on. Or maybe it would be possible to invent some control system which would drop the revs automatically.
__________________
"Parce que je suis heureux en mer, et peut-Ítre pour sauver mon ame. . . "
Dockhead is offline   Reply With Quote
Old 05-11-2017, 08:32   #11
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 16,856
Re: WHAT IS A GOOD GENERATOR ??

An issue with having a pure DC generator is how good a battery charger will it be?
There are many, very good, very sophisticated AC battery chargers.
However the biggest problem with a pure DC genset in my opinion is their relative non availability. In truth I have never seen one.
As much as I like Science projects I have decided to as much as possible to buy off the shelf as opposed to trying to roll my own, watermaker for example. They are not Rocket Science.
Same for a generator.
Itís so easy now to convert back and forth between AC and DC with decent efficiency that even if you only want DC power, an AC generator still makes sense based on cost and availability.
__________________
a64pilot is online now   Reply With Quote
Old 05-11-2017, 08:51   #12
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 16,856
WHAT IS A GOOD GENERATOR ??

Quote:
Originally Posted by Dockhead View Post
Those look good to me, too. Can you give details about your experience?


Many of us have them.
Biggest draw is cost, size, weight and fuel consumption. Itís small and with the sound enclosure included only weighs 200 lbs, 160 without the sound enclosure. Two people can easily carry it and lower it into a Lazarette.
I donít have enough Boat to warrant a full size gen, and I didnít want to lose the storage space, and gain all that much weight. I have a 30amp electrical system so anything over 3.5 KW I couldnít use anyway without rewiring the Boat.
I have always been amazed when I see a Cat with a huge, heavy generator. I would have thought that the weight wouldnít be wanted.
According to the guy at Nex Gen they have many on shrimp boats etc that have over 5000 hours, he says very few if any actually wear out, itís usually disuse and corrosion that gets them.
It is louder and not as smooth as a NL or other 1800 RPM gen, itís actually a mid RPM as it runs at I believe 2850 RPM and drive the gen head through a serpentine belt at 3600 RPM.
The motor is a Kubota single cylinder horizontal Diesel used primarily on garden equipment, construction dirt tampers and the like.
It oddly enough has a ball bearing crankshaft, and I believe a wet cylinder, so it ought to be childís play to overhaul. However as the cost isnít all that bad and since itís compact and only weighs 160 lbs, likely if or when mine wears out Iíll likely just replace it with a couple of hours work to R&R.

They are capacitor regulated, not an AVR so simple but not as sophisticated. I learned you can change the voltage by slightly changing the Uf of the capacitor.

If your the type that cranks the generator before you unplug from shorepower and it runs until you return to the dock, then this may not be your generator, but if you want to run it a couple of times a week to make water, charge batteries or when itís hot and the mosquitos come out, itís great for that. Think of it as a big, built in Diesel Honda.
__________________
a64pilot is online now   Reply With Quote
Old 05-11-2017, 09:03   #13
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,641
Re: WHAT IS A GOOD GENERATOR ??

Quote:
Originally Posted by a64pilot View Post
An issue with having a pure DC generator is how good a battery charger will it be?
There are many, very good, very sophisticated AC battery chargers.
However the biggest problem with a pure DC genset in my opinion is their relative non availability. In truth I have never seen one.
As much as I like Science projects I have decided to as much as possible to buy off the shelf as opposed to trying to roll my own, watermaker for example. They are not Rocket Science.
Same for a generator.
Itís so easy now to convert back and forth between AC and DC with decent efficiency that even if you only want DC power, an AC generator still makes sense based on cost and availability.
Yes, I agree about conversion efficiency, and I don't care that much whether I generate AC or DC power.

But a DC generator like this has some profound advantages. Note that I do NOT list "getting DC power directly" as an advantage

* Can run at different RPMs so that engine runs with a more healthy load for a given RPM.

* Cutting back the revs when small power is needed, will be quieter and less wear on the engine, not to mention more healthy.

* Using a standard school bus alternator (or a pair of them) is cheap, easy to repair, easy to carry a spare for -- in other words, easier to keep running in remote locations.

* Separating engine from generator makes both easier to get at and service.


Making it into a good battery charger is trivial -- a good external controller will do that -- Balmar or Sterling.
__________________
"Parce que je suis heureux en mer, et peut-Ítre pour sauver mon ame. . . "
Dockhead is offline   Reply With Quote
Old 05-11-2017, 09:09   #14
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,641
Re: WHAT IS A GOOD GENERATOR ??

Quote:
Originally Posted by a64pilot View Post
Many of us have them.
Biggest draw is cost, size, weight and fuel consumption. Itís small and with the sound enclosure included only weighs 200 lbs, 160 without the sound enclosure. Two people can easily carry it and lower it into a Lazarette.
I donít have enough Boat to warrant a full size gen, and I didnít want to lose the storage space, and gain all that much weight. I have a 30amp electrical system so anything over 3.5 KW I couldnít use anyway without rewiring the Boat.
I have always been amazed when I see a Cat with a huge, heavy generator. I would have thought that the weight wouldnít be wanted.
According to the guy at Nex Gen they have many on shrimp boats etc that have over 5000 hours, he says very few if any actually wear out, itís usually disuse and corrosion that gets them.
It is louder and not as smooth as a NL or other 1800 RPM gen, itís actually a mid RPM as it runs at I believe 2850 RPM and drive the gen head through a serpentine belt at 3600 RPM.
The motor is a Kubota single cylinder horizontal Diesel used primarily on garden equipment, construction dirt tampers and the like.
It oddly enough has a ball bearing crankshaft, and I believe a wet cylinder, so it ought to be childís play to overhaul. However as the cost isnít all that bad and since itís compact and only weighs 160 lbs, likely if or when mine wears out Iíll likely just replace it with a couple of hours work to R&R.

They are capacitor regulated, not an AVR so simple but not as sophisticated. I learned you can change the voltage by slightly changing the Uf of the capacitor.

If your the type that cranks the generator before you unplug from shorepower and it runs until you return to the dock, then this may not be your generator, but if you want to run it a couple of times a week to make water, charge batteries or when itís hot and the mosquitos come out, itís great for that. Think of it as a big, built in Diesel Honda.
Sounds very good!

Is it reliable? Have you had any trouble with yours?
__________________
"Parce que je suis heureux en mer, et peut-Ítre pour sauver mon ame. . . "
Dockhead is offline   Reply With Quote
Old 05-11-2017, 09:44   #15
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29į 49.16í N 82į 25.82í W
Boat: Pearson 422
Posts: 12,334
Re: WHAT IS A GOOD GENERATOR ??

Quote:
Originally Posted by Dockhead View Post
Sounds very good!

Is it reliable? Have you had any trouble with yours?
Bill Trayfors (btrayfors) has had one of these for years and has been happy with his. The only problem he reports, unloaded the AC wave form is kind of dirty and his inverter wouldn't kick in and sync with it unless he first added some kind of pure resistive load, then no problem.

I think later generations have fixed this but maybe A64 has some experience in this area.

You might also PM Bill to see if he has any new comments.
__________________

__________________
The water is always bluer on the other side of the ocean.
skipmac is online now   Reply With Quote
Reply

Tags
generator

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Good Food, Good Flavor, Good Value, Good Packaging Steady Hand Provisioning: Food & Drink 22 23-05-2016 17:26
Portable Generator vs Solar Panels or Wind Generator Sweet As Electrical: Batteries, Generators & Solar 120 16-09-2010 19:27
Good Morning, Good Evening and Good Night bullitt774 Meets & Greets 10 30-08-2010 15:35
Any way to convert a DC Generator to an AC Generator? Latitude9.5 Engines and Propulsion Systems 13 06-04-2007 12:06



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:30.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.