How safe is it to use a generator?

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Sep 5, 2007
689
MacGregor 26X Rochester
The difference between many AUX engines charging at anchor and a Honda is that the main engine is a tick above idle, inside your boat, and using a wet exhaust.
Would it be a fair conclusion, based on that statement, that a better use of generator boat bucks would be to buy a larger alternator for the auxiliary, so that it can perform faster charging at lower engine speed, and end the noise (primarily water splash, but not completely) sooner?

Definitely not trying to throw gas on this discussion, but I've seen recent write-ups on some new high-performance alternators for inboards, but don't know how suitable they would be with small house banks. My last boat had the OEM alternator that came with the 27 hp GM30F (unknown output), and I always wondered if a larger alternator would have been a good investment when I only had a pair of group 24 deep-cycle batts and no solar, wind, water, or generator. Extended time without engine or shore power was always a concern.

Don't have the boat any more, so it's moot for me, but I just like to know things, and a higher output alternator sounds like it could possibly be a decent work-around for a separate generator unit, and possibly cheaper.
 
Sep 5, 2007
689
MacGregor 26X Rochester
Oh, and I think the OP handled it exactly the right way. The FIL was trying to do a nice thing, and it's best that the admiral was witness to the racket and unsuitability of the unit.

HF will take it back, by the way. Put the money towards another method for charging, or a larger inverter, or a butane stove, or whatever need there is that the generator was supposed to fill. Or just give it back to the FIL.
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
Would it be a fair conclusion, based on that statement, that a better use of generator boat bucks would be to buy a larger alternator for the auxiliary, so that it can perform faster charging at lower engine speed, and end the noise (primarily water splash, but not completely) sooner?
Excellent point. It doesn't work for everyone, though, as some have smaller boats with outboard motors.

What I simply don't understand is what folks with larger boats, with inboard main engines, are using these generators for, other than for A/C. Maybe someone can enlighten me. If it's just a microwave, or perhaps a hair dryer, it seems a bit much. If it's for television or computer use, for lack of an inverter or larger house bank, I can see why but couldn't be bothered myself. Electric cooking someone mentioned? Wow, seems bizarre on a boat, but what do I know.

Wouldn't if be cool if Honda would make a diesel version of the EU1000 or EU2000, with an available "adapter kit" for inboard installation? Wow, that would be so nice! But, a pretty tough requirement to fulfill, mostly because of cooling it.
 
Sep 5, 2007
689
MacGregor 26X Rochester
It doesn't work for everyone, though, as some have smaller boats with outboard motors.
Including the OP. I had forgotten he has an H240, which (AFAIK) has an OB for auxiliary power.
 

kenn

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Apr 18, 2009
1,271
CL Sandpiper 565 Toronto
What I simply don't understand is what folks with larger boats, with inboard main engines, are using these generators for, other than for A/C. Maybe someone can enlighten me. If it's just a microwave, or perhaps a hair dryer, it seems a bit much. If it's for television or computer use, for lack of an inverter or larger house bank, I can see why but couldn't be bothered myself. Electric cooking someone mentioned? Wow, seems bizarre on a boat, but what do I know.

Wouldn't if be cool if Honda would make a diesel version of the EU1000 or EU2000, with an available "adapter kit" for inboard installation? Wow, that would be so nice! But, a pretty tough requirement to fulfill, mostly because of cooling it.
You got the idea. Gennies will power A/C and the other high-draw AC thingies that some people can't leave the dock without (not my idea of fun either, but whatever). Generators also provide faster charging when needed.

We use a butane stove onboard for cooking and for heating water - convenient, efficient, cheap, and safe. And very very quiet. And the same folding Melitta filter-holder linked-to by The Garbone :).

Yes there are small diesel water-cooled generators available, but once you add the plumbing and the sound-proof case, you're back over $6k again.
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
Generators also provide faster charging when needed.
Thanks for the reply. I don't think the above statement is true, not for the portable generators.

Taking the Honda EU1000 as an example, its DC charging output is 8A max. If you connect the AC output to your shore power connector and use your shore power charger, you are limited to that, which is likely in the 10A to 40A output range, probably most commonly 20A or less.

Compare this to your main engine alternator which can be as much as 100A or more in bulk. Mine is typically around 85A for a house bank down to 60% or so. Spends most if its time around 50A.

Charging with the engine is much, much faster than with a portable generator.

At one time I had considered converting one of these for high-output DC, but there are too many other projects in the way.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Excellent point. It doesn't work for everyone, though, as some have smaller boats with outboard motors.

What I simply don't understand is what folks with larger boats, with inboard main engines, are using these generators for, other than for A/C. Maybe someone can enlighten me. If it's just a microwave, or perhaps a hair dryer, it seems a bit much. If it's for television or computer use, for lack of an inverter or larger house bank, I can see why but couldn't be bothered myself. Electric cooking someone mentioned? Wow, seems bizarre on a boat, but what do I know.

Wouldn't if be cool if Honda would make a diesel version of the EU1000 or EU2000, with an available "adapter kit" for inboard installation? Wow, that would be so nice! But, a pretty tough requirement to fulfill, mostly because of cooling it.
In general, it is not good to idle your diesel with no load like you would just to charge batteries. So going to a high output alternator if your plan is to sit on the hook or a mooring and run your engine to charge your batteries is not a good idea.

As I said somewhere earlier in this thread, we plan to add solar panels for our primary recharging when we leave to go cruising. Our secondary will be a Honda EU2000i Companion generator. The generator will be used to charge the batteries when necessary due to cloudy weather for multiple days. It will also be used to power tools for boat projects/maintenance. It may even be used to heat up water in our hot water heater for showers and the like.

TV, computer recharging, camera recharging, radio, lights, fans, etc. will all be 12 volt and will not require the use of the generator. We will also ditch the microwave, so that will no longer need to be powered.

As to the electric cooking, there used to be Coast Guard regulations that forbid the use of propane on charter vessels. So there are a number of older boats that should have propane systems but don't because of this now changed regulation. They could be changed over now but like anything else on a boat, it coasts a fair amount of money. So many have chosen to live with the eclectic cooking instead of incurring the expense of changing over to propane.
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
In general, it is not good to idle your diesel with no load like you would just to charge batteries. So going to a high output alternator if your plan is to sit on the hook or a mooring and run your engine to charge your batteries is not a good idea.
For millions of sailboats running the main propulsion diesel is de rigueur for charging batteries, including everything from affordable, 20-something footers to 1/2 million dollar plus coastal cruisers (from Morris Yachts, for example). So while you may have a theoretical point, in practical terms it is meaningless. To paraphrase you: in general, it doesn't matter.

I don't idle mine, I usually run it at 1000 RPM or slightly higher. I don't get enough of a difference in output at higher RPMs to make it worth the extra noise. At idle (700 RPM) it doesn't make enough voltage to charge beyond a float level.

The only potential negative effects are glazing of the cylinder walls over time, that may cause some smoking. Mine has not exhibited this in 29 years of operation (at about 3000 hours). And, if it becomes necessary it is correctable: Westerbeke used to run generators on a dyno at 80% load with a teaspoon of feldspar in each cylinder to roughen up the cylinder walls and stop the smoking! (maybe they still do). You can break the glaze with a hone pretty quickly when it's time, like every 40 years or so. :) Probably won't even need new rings.

A big charging load, taking conversion efficiencies and drag into account is about 3 or 4 HP, which is about 15 to 20% of max rated output for this engine; so, hardly idling.

A bonus is that it heats the domestic water, too.

I don't think the EU2000 has a DC output; so, you'll have to run the AC into a battery charger. Unless you have a huge charger it will take forever to bring a decent house bank back from 60 or 70% SOC. Well, not exactly forever, but probably 8 or more hours. How big is your house bank? How big is your battery charger? You could get a 60A charger for about $500 that the Honda will power. An 80A charger, for about $1000 to $1500, requires more input current than the EU2000 will supply.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
For millions of sailboats running the main propulsion diesel is de rigueur for charging batteries, including everything from affordable, 20-something footers to 1/2 million dollar plus coastal cruisers (from Morris Yachts, for example). So while you may have a theoretical point, in practical terms it is meaningless. To paraphrase you: in general, it doesn't matter.

I don't idle mine, I usually run it at 1000 RPM or slightly higher. I don't get enough of a difference in output at higher RPMs to make it worth the extra noise. At idle (700 RPM) it doesn't make enough voltage to charge beyond a float level.

The only potential negative effects are glazing of the cylinder walls over time, that may cause some smoking. Mine has not exhibited this in 29 years of operation (at about 3000 hours). And, if it becomes necessary it is correctable: Westerbeke used to run generators on a dyno at 80% load with a teaspoon of feldspar in each cylinder to roughen up the cylinder walls and stop the smoking! (maybe they still do). You can break the glaze with a hone pretty quickly when it's time, like every 40 years or so. :) Probably won't even need new rings.

A big charging load, taking conversion efficiencies and drag into account is about 3 or 4 HP, which is about 15 to 20% of max rated output for this engine; so, hardly idling.

A bonus is that it heats the domestic water, too.

I don't think the EU2000 has a DC output; so, you'll have to run the AC into a battery charger. Unless you have a huge charger it will take forever to bring a decent house bank back from 60 or 70% SOC. Well, not exactly forever, but probably 8 or more hours. How big is your house bank? How big is your battery charger? You could get a 60A charger for about $500 that the Honda will power. An 80A charger, for about $1000 to $1500, requires more input current than the EU2000 will supply.
First lets clear up some language issues. Idling is running your motor in neutral. Even if you bring the RPMs up to 1,000 you are still idling your motor.

Maybe part of it is a difference in engines. As you pointed out, running the diesel with no load can glaze the cylinder walls and cause excessive smoking. On the diesel in my C310 it also cause wear of the damper plate. Replacing that involves disconnecting the transmission and typically pulling the engine off its mounts. Most are having this problem at under 600 hours. There are plenty of other problems that can develop plus the additional wear on an important piece of your boat that isn't needed and not easily replaced.

Plus, you are basing things on your use, 3K hours in 29 years (so like 100 hours a year). If you are cruising, like a lot of the people who have commented about using Honda generators on this thread are doing or planning on doing, you can put 3K hours on your boat in a year. So your experience based on the extremely light use of your motor isn't too relative under a cruising scenario.

If you are only spending one or two nights a week or a month on the hook, this seems like a good option. But if you are spending more time then that, it might be time to look for something else. Of course the best alternative would be a marine generator but that will run you around $5K plus take up significantly more weight than a Honda suitcase generator.

Also, you haven't taken into account the efficiency of the two motors. My diesel is very efficient and only uses 0.5 gallons per hour. Others with older diesels may easily be twice that. The Honda can run for 4-6 hours on 0.5 gallon of fuel. So that would need to come into the equation.

Lastly, there are things that the Honda could do that isn't possible with out a generator. Powering tools for instance. Sure, you could put in a large inverter but that would be very inefficient and could be much more costly than the $1,000 for the Honda.

Oh, by the way, going to a larger 120v charger doesn't really help because you will be limited based on the generator. So my 40A charger would do just fine. In fact, I wouldn't even be able to charge at the full 40A.
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
I don't agree on your definition of idling. Idling is an engine running at rest, i.e., idle speed, no load. I think most would agree with me.

I run power tools like a 1/2" drill, saber saw, etc., with my inverter, which is only 750W. Works fine. I paid about $60 for it, and it's permanently installed, with a 100A breaker on the DC side. There's a switch w/interlock to light up the boat's outlets.

The main engine with the alternator attached is a generator, after all. The fact that the Honda happens to have an inverter inside (it does) and mine is disaggregated doesn't change this.

But I am a bit puzzled. If you are cruising, and running the engine 3,000 hours per year - which is 8.3 hours per day for 365 days of cruising - why would you need a generator? Just make sure you have enough house battery capacity. If you are not cruising, and on a mooring, and run the fridge only when you are away somewhere, why not just charge the batts with the engine? With a decent alternator/regulator and house batts in good condition this is at worst only 1.5 hours a day. When I'm anchored for more than one day I deploy a 51 Watt solar panel, and often don't have to run the engine at all.

I'm not worried about fuel. I only burn about 0.4 gal.hr, and I have a 32 gallon fuel tank. While the Honda is apparently more efficient, it makes significantly less power for charging per unit time, and has a much smaller tank. You'll need to carry a gas can, and transfer gas, etc. A mess I don't need.

One thing I can do that the Honda can't is charge the batteries and make hot water at the same time. This becomes a rather easy routine.

I simply don't get the whole portable, gas generator on a boat thing. I don't need any more stuff, volatile liquids, more routines, less storage space, and more risk than I already have.
 
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
My buddy Darren owns a good sized excavating, irrigation and landscaping company in Colorado and we talk diesels quite a bit. Just got to see him last week.. He has a good sized fleet of them and a couple of them have over 20k hours with no rebuilds. The last time I spoke with him about engine longevity he had one Yanmar block and one Mitsubishi block with over 20k hours. He bought both of these machines used with about 5k hours on them back in the late 90's.

Most of his smaller engines are either Yanmar or Kubota but he does have a few Mitsubishi's too. His engines run all day and never shut off and they idle for long, long, long hours. Now granted these are not in a marine application but in well over 500,000 hours of combined run time on his fleet he has yet to rebuild an single small diesel engine. All his machines run Shell Rotella and it gets changed regularly. Of course he buys his oil in 55 gal drums and I buy it by the gallon...;)

If heavy equipment running Yanmar, Mitsubishi and Kubota blocks can rack up10k to 20k hours, while doing hundreds and hundreds of hours of idling per year, with no rebuilds then a well maintained marine diesel should be able to do the same.

When we had the discussion about not letting diesels idle a few years ago he just laughed about the glazing the cylinder walls. His sarcastic comment was something like "Sh&t I better let my guys know not to let them idle";). Course he'd already been doing it for 20 some odd years, with no failed engines or rebuilds needed, so he was surprised to find out his engines were going to die soon...;)

Our engine has idled perhaps half or more of its 3600+ hours. It burns ZERO oil, has cross hatching in the bores that looks like new and she purrs like a kitten. We have Sea Frost and often sail with the engine idling or will let it idle to chill the plate if we are alone and not disturbing others. Our boat also did a five year 24/7 on-the-hook almost circumnavigation. She had no generator and only the factory alt and a single solar panel. The batteries lasted six years and were still kicking..
 
Nov 22, 2011
1,246
Ericson 26-2 San Pedro, CA
A few years ago I was in the anchorage at Isthmus Cove, Catalina for a few days. I did not have my normal complement of batteries installed that particular trip so I needed to run my main engine to recharge (no generator). I'm Atomic 4 powered so I'm pretty quiet except for the normal sploosh of a wet exhaust.

Nevertheless, prior to recharging I made a dinghy trip around the anchorage to ask my neighbors when would be the least offensive time to do this. They were most appreciative of the consideration, a suitable time was chosen (like around midday) and we all got along fine.
I'd say you went the extra mile there, Neil, considering how quiet an Atomic 4 runs. Heck, people pay good money for electric waterfalls and fountains just to get that Atomic 4 "sploosh, sploosh" sound in their backyards! And you were providing it for FREE! :D

Still, I think that's a great thing to do and I wish more would follow suit. What I really love is when I'm at Avalon and some clown fires up one of those really loud generators located on the bow of his boat, and then takes off in his dinghy for two or three hours. I mean, obviously he can't be expected to endure all that obnoxious noise for hours on end! :cussing:
 
Nov 22, 2011
1,246
Ericson 26-2 San Pedro, CA
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
Perhaps I am wrong on the need for a generator on a cruising boat. I think I need to explore this further.
JK,

I think the problem with the damper plates stems from..

1- Chronically low idle RPM. Universal allows for up to 1200 RPM at idle on the M-25's I find most of them need to be above 1000RPM just to idle smoothly.

2- Catalina IMHO chose a cost saving damper plate. The "C" in M-25 XPB-C means Catalina's spec... I have seen the Sachs plates go 4500+ hours. I swapped ours out at about 2800 and it still worked fine but it was a "while you're in there" sort of thing.
 

zeehag

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Mar 26, 2009
3,198
1976 formosa 41 yankee clipper santa barbara. ca.(not there)
i have had honda 2000--it is actually one of the only ways to efficiently use tools on a boat while cruising.
when i do not use marnas i used honda--i gave it to my mechanic--i will buy another at a later date, as i do use tools and vacuum cleaners while anchored, and it does the job. the 1000 didnt do it--was too wimpy. but the 2k is a good generator. even has an eco switch that keeps rpms lower and actually silences the noise some.
perhaps a smaller boat may not need such items as power tools and repairing equipment, as the smaller boats usually head into port to marinas when weather changes for the year---- but the larger ones use these items full time permanently and have no problems.
 
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