Honda Portable Generator: Will This Work?

[boatpoker]

Originally Posted by Augi

However since my initial post the "solution for a portable generator in a locker" has evolved to include industrial grade ac blower for ventilation and exhaust. And includes using a shroud that goes over the entire exhaust end of a Honda portable(see link). Store. The exhaust will exit out the next to last step with a flapper valve to prevent water ingress. The generator and exhaust blower would be 2 ft.

Not much difference between gasoline and propane in regards to fume containment, ventilation and ignition protection (have you sourced an AC ignition protected blower ?)

You may want to look at these.
Safe Boat Propane System Installation

Safe Ventilation of Gasoline Engine Compartments

[flyingfin]

Originally Posted by Granfalloon

Tethered to the swim platform. At anchor, the boat would turn into the wind. Always have 1-2 battery-powered CO alarms.

Ditto: We see small I/O cruisers in Florida doing this all the time, lash fuel tank & Honda gen set to dive platform and run their A/C at nite, then microwave in morning to cook.

[jmh2002]

This might be more catamaran thinking than monohull, but electrical concept wise, just like with inverters, I like the idea of having 2 x 2000 Hondas that can be paralleled together.

So again the same like inverters, with both running at the same time you can run everything onboard at once if necessary, but if loads are low, or one fails, you can manage what loads are running and easily survive with 1 genset and 1 inverter until repairs can be effected.

I accept that this is more of a long distance remote cruising orientated setup and is not exactly what the OP was asking about.

Needing to run AirCon all night limits your options. Even if you solve the safety aspects of the Honda, you will still need to listen to it for the same amount of hours that you want to run the AirCon.

That might become tiresome if it's on a daily basis.

You could mitigate that with a serious LiPo and Solar setup, but that is also expensive and adds weight too, so also may not be suitable for the OP's stated usage.

[a64pilot]

Another issue with propane is expense. Beside the consumption of fuel is higher as propane has less BTU per unit volume than gasoline.
Propane cost is not that bad if you buy it a couple hundred gallons at a time for your home, but to get a small bottle filled you pay about $4 a gl in the US, and exchanges are even more expensive, about $5 to $6 a gallon.
A 20 lb tank holds just under 5 gl so you will go through a tank every other day or so, depending on how many hours you run it of course.

[sailjumanji]

On previous boat, we had a Dometic Turbo 8000 btu air con. The Honda 2000 would run it for 8-10 hrs on one fill (0.9 gal). Initially it would run hard, but around mid ight when cabin 70 deg the compressor would start running intermittently so the Honda would miser in eco mode.

On the new cat, we have an 18k btu air xon and a Honda 2200. It takes much longer to cool cabin, so we only get 6-7 hours out of the tank. By then, its dark and cool, so we just live with the generator and air con going off. Alternitive is to use a separate gas tank with one of those honda replacement fuel caps. Then you can draw from a 3.5 gal portable tank and much longer run time. Plus its easier to pour gas into portable tank without spillage, instead of trying to get honda fank filled to top.

These are my experiences in Texas and Florida, where it gets pretty hot. On my old cat, we unhooked one of the fuel lines from the outboard motors and clipped it to a fuel hose extension with the honda cap. That essentially gave us unlimited run time off the boat fuel tank (35 gal).

I think the biggest issue with the honda is getting it low enough so that exhaust vapor cannot come aboard, while at the same time protecting it from rain. The later being the most difficult as when snuggled up in 70 deg air in bed with air con running, its sometime hard to hear light rain on deck. ;-)

[a64pilot]

Ref the replacement caps, I’ve only had a couple, and neither was any good. To start with the gasket they had wasn’t fuel proof, so it would soften and swell and leak, any leak lets in air of course and the cap doesn’t work.
Then the threads weren’t “quite right” so what I ended up doing was removing the vent from the factory cap which you can do without breaking anything and tapping the hole and installing an outboard fitting, that way my dinghy fuel tank and line can be used for an extended run tank. Keep the vent because it can be reinstalled.
I threw the aluminum cap in the drink. If anyone knows of a good one that has accurate threads that won’t strip the Honda tank if tightened tight and has a fuel proof gasket I’d appreciate a link.

[Augi]

Originally Posted by boatpoker

Not much difference between gasoline and propane in regards to fume containment, ventilation and ignition protection (have you sourced an AC ignition protected blower ?)

You may want to look at these.
Safe Boat Propane System Installation

Safe Ventilation of Gasoline Engine Compartments

Excellent links! Thanks. Very helpful.

[Augi]

Originally Posted by a64pilot

Another issue with propane is expense. Beside the consumption of fuel is higher as propane has less BTU per unit volume than gasoline.
Propane cost is not that bad if you buy it a couple hundred gallons at a time for your home, but to get a small bottle filled you pay about $4 a gl in the US, and exchanges are even more expensive, about $5 to $6 a gallon.
A 20 lb tank holds just under 5 gl so you will go through a tank every other day or so, depending on how many hours you run it of course.

Thanks for the feedback!

We are not full time live a board cruisers so the added expense of propane vs, gas is not an issue. But I understand a Honda 2200 does not provide as much output using propane vs. gas. Don't know yet, if true propane provides less power, if it would effect our use enough to make a difference.

[valhalla360]

Originally Posted by a64pilot

I
What I can’t figure out, is why do most of the bigger Cats have 12 KW generators or larger? 12KW is 100 amps, what boat can draw 100 amps?
I have dual chargers and can charge 185 amps, which is also pretty close to high 20’s in amps, so it’s all the 3.5 can handle.

Somewhere in the 8-10kw range is probably enough for most but...

Once you get over 40ft, it's common to have a couple air/con units...often 3 units...if they are each pulling 15amps, that's already 45amp.
- A big battery charger can pull 8-10amps.
- Electric Hot Water Heater can pull another 12-15amps.
- Electric stove can add 10-20 amps.
- Misc small draws can add 4-5 amps.

I'm guessing the incremental cost jumping from 8kw to 12kw isn't much when you figure install is probably a wash on a new boat.

Sure you can manage your power usage but people dumping $500-1,000k into a boat expect to be able to just use it.

[Augi]

Originally Posted by sailjumanji

On previous boat, we had a Dometic Turbo 8000 btu air con. The Honda 2000 would run it for 8-10 hrs on one fill (0.9 gal). Initially it would run hard, but around mid ight when cabin 70 deg the compressor would start running intermittently so the Honda would miser in eco mode.

On the new cat, we have an 18k btu air xon and a Honda 2200. It takes much longer to cool cabin, so we only get 6-7 hours out of the tank. By then, its dark and cool, so we just live with the generator and air con going off. Alternitive is to use a separate gas tank with one of those honda replacement fuel caps. Then you can draw from a 3.5 gal portable tank and much longer run time. Plus its easier to pour gas into portable tank without spillage, instead of trying to get honda fank filled to top.

These are my experiences in Texas and Florida, where it gets pretty hot. On my old cat, we unhooked one of the fuel lines from the outboard motors and clipped it to a fuel hose extension with the honda cap. That essentially gave us unlimited run time off the boat fuel tank (35 gal).

I think the biggest issue with the honda is getting it low enough so that exhaust vapor cannot come aboard, while at the same time protecting it from rain. The later being the most difficult as when snuggled up in 70 deg air in bed with air con running, its sometime hard to hear light rain on deck. ;-)

Thanks for the feedback!

Do you use a soft start to run your 18,000 BTU air cond. with your Honda 2000?

Exhaust is one thing and some of the exhaust, I guess, is heavier than air. But CO is slightly lighter than air. So getting the portable generator lower, (everything else being equal, which it never is), may not help with the CO issue. That is why some posters are suggesting hanging the portable generator from the boom or main halyard. But that approach is not good for the noise issues especially for any boats anchored nearby but helps with vibration.

[valhalla360]

Originally Posted by a64pilot

I don’t think the Honda uses much more fuel. It’s claimed to run for 3 to 8 hours depending on load and holds a gallon of fuel. My little Nexgen burns a quart an hour at 50% load so four hours per gallon/
Honda 3.2 hours making 13.3 amps on 1 gl of fuel
Nexgen 4 hours making 14 or so amps on 1 gl of fuel.

The modern portable inverter generators can probably hang with the old style 1800rpm unit in terms of efficiency as they do a very good job of throttling back when the load drops off. Plus they don't have the parasitic losses from a water pump or push exhaust thru a long pipe.

If you are running them at peak output 100% of the time, the old style 1800RPM diesel units may win out but if it's a 30% duty cycle, I wouldn't be surprised in the portable inverter generator wins out.

[rslifkin]

A lot of boats do have over-sized generators for convenience. But it's not necessarily good design. My boat has 2x 50A/125V shore power inlets, so it would take a 12kw generator to be equivalent. My generator is only 6.5kw (54 amps), but I've never found it too small. No, it won't run everything on the boat at the same time, but I also rarely do that. With a little attention to loads, it's easy to run anything I'd want to on the generator. I've never had a need to use the microwave, all 3 stove burners, and all 3 A/C units while the battery charger and water heater are both going full blast. That's technically possible on shore power (but not the generator). In reality though, it's more of an academic exercise.

Originally Posted by valhalla360

The modern portable inverter generators can probably hang with the old style 1800rpm unit in terms of efficiency as they do a very good job of throttling back when the load drops off. Plus they don't have the parasitic losses from a water pump or push exhaust thru a long pipe.

If you are running them at peak output 100% of the time, the old style 1800RPM diesel units may win out but if it's a 30% duty cycle, I wouldn't be surprised in the portable inverter generator wins out.

Gas engines lose far more efficiency than diesels do as load is reduced. The inverter units mitigate this somewhat by being able to throttle the engine down. However, the actual generator head efficiency is worse with the inverter in the loop. So in the end, compared to a same-output diesel generator, they're a little less efficient at light load and significantly less at heavy load. Air cooled engines are horribly inefficient in general. The comparison I gave earlier to my old Onan unit is Honda vs 1800 rpm 2 cylinder gas powered flathead with a primitive carb. Under light load, the Honda is slightly more efficient. At rated load for each unit, the Honda is notably less efficient despite having far more tech on its side (fuel injection, newer engine design, etc.)

[Augi]

Originally Posted by a64pilot

I don’t think the Honda uses much more fuel. It’s claimed to run for 3 to 8 hours depending on load and holds a gallon of fuel. My little Nexgen burns a quart an hour at 50% load so four hours per gallon/
Honda 3.2 hours making 13.3 amps on 1 gl of fuel
Nexgen 4 hours making 14 or so amps on 1 gl of fuel.

I think the difference if any can be put down to measuring errors, I’m certain that the Nexgen fuel consumption wasn’t as scientifically derived as Honda’s.

Little Honda is not inefficient, it’s relatively inefficient at high load, but gains in efficiency at lower loads when the RPM comes down, so if you only need 6 or 8 amps or so, I bet the Honda burns less fuel than the Nexgen, cause the Honda can go as long as 8 hours on 1 gl and the Nexgen can’t. Plus if you only need a couple of hundred watts, the Honda purrs at idle, and a Diesel should be loaded a little more than that, but the Honda is happy

Now many put a lot of stock into the Honda varying RPM, but astonishingly it’s lowest RPM with eco mode on and zero load is 3000 RPM, and it goes up to I think 4300 RPM eco mode switch off and at max continuous power, now it will get up past 5000 RPM or so if you overload it, and it will produce at least 17 amps of power, but your exceeding its limits, and I don’t know for how long it will do that, but I’ve seen it make 20 or so amps before I realized I left the water heater breaker on and turned it off.
It’s rated for a 2000 for 16 amps max, and 13.3 continuously, but as I said it will make much more.

Where that matters is start up loads for a watermaker pump or airconditioner or whatever, the Honda can jump up to 20 amps for a short time, most others can’t.
The Nexgen due I’m sure to its high flywheel inertia can take a 70 amp surge. The Nexgen 3.5 and 5.5 are identical generators, what limits the 3.5 is engine power, but the generator head is fine making 5.5 kw, if the little motor could.

On edit, the Nexgen 5.5 is not an 1800 rpm motor, it turns 2800 just like the 3.5

I stand corrected on Next Gen RPM!

However, the smallest(4.5 KW) Phasor 2 cylinder generator runs at 1800 RPM according to their specs(see link).

https://www.phasormarine.com/k2-4.5pmg.html

[Rohan]

Originally Posted by vpbarkley

you could place the generator in a dinghy tied aft, where heat, vibration, racket, exhaust gasses and fire potential would be external to the boat.

Until wind or wave knocks it over and shorts out the generator.

[valhalla360]

Originally Posted by Rohan

Until wind or wave knocks it over and shorts out the generator.

Not to mention, you won't notice it got stolen until the cabin heats up and you go to check what happened.