Portable Honda Gen to Shore Power- Can this power hot water electrics?

[Ted and Relinda]

our Honda 2000 heats the hot water tank with o problem. Most 6-10 gal. hot water tanks have a 1500 w. element. I dont charge at the same time as heat..

[Russ]

Wannacat

Is your Honda hard wired into the boats AC system. If not how do you get AC to the water heater. Thinking if ditching my hard wired diesel genny for cheaper smaller simpler Honda. Thanks.

[Ted and Relinda]

Our Honda is not hard wired in. I set it on the aft deck area and plug it into the shore power with a step up pigtail,,,,found in most RV stores or Walmart..
Ted.

[wannacat]

Russ, I converted a shore power cord that I picked up at a flea market, I put a 120V male plug on the one end to plug into the portable gen and the other goes directly into my 30 amp shore power plug, Then I can selectively run anything on the 120 V boat circuits as I want.

[CapnBazza]

Originally Posted by simonpickard

Hello all,

I was going to post this in another thread dealing with using Portable Generators such as the Honda to shore power, but they were closed.

As the title says really, can you use these portable generators to plug into the shore power and charge batteries + the hot water?

Or aren’t they powerful enough to do this?

Regards,
Simon

Another related question but not considering wattage etc. .....
When I plugged my pure sine wave 3000w inverter into the shore power inlet, the “floating ground” inverter produced unexpected voltages in the shore power circuit. I had 237v between Hot and Neutral, 168v between Neutral and Earth and 77v between Hot and Earth. Any appliance plugged in resulted obviously in the ELCB tripping instantly. Do portable generators such as the Honda and Yamaha have the same issues?

To overcome the problem I have used the inverter to power up three seperate double pole outlets and all works fine.

[Lancerbye]

I had a problem with my main built in generator last year so I purchased a Honda 2000i hoping to just plug it in to the boats 30 amp shore power cord set since it does have a twist lock 30 amp receptacle on it. However when I tried to do this the Honda would rev up and go into overload protection mode. I ended up using it by bypassing the 2500 watt inverter charger and going straight to my smaller fixed battery charger and directly to the appliances I was using. It seems that the inrush current of the inverter charger, which starts the charge at 120 amps, was too much even though theoretically it should have worked.

[a64pilot]

Originally Posted by Lancerbye

I had a problem with my main built in generator last year so I purchased a Honda 2000i hoping to just plug it in to the boats 30 amp shore power cord set since it does have a twist lock 30 amp receptacle on it. However when I tried to do this the Honda would rev up and go into overload protection mode. I ended up using it by bypassing the 2500 watt inverter charger and going straight to my smaller fixed battery charger and directly to the appliances I was using. It seems that the inrush current of the inverter charger, which starts the charge at 120 amps, was too much even though theoretically it should have worked.

My Magnum inverter / Charger is adjustable.
I turn the 125 amp charge down to 80% and it charges at 100 amps, which pulls right at 13 amps on the generator, which is right at the continuous duty limit of a Honda 2000.
I can make 35 gls of water an hour with my my cruise RO which pulls about 9 amps, I turn the battery charger to 20% and can charge the bank at about 30 amps and stay within the Honda’s limits, both together pull about 12 amps.

We can heat water with it and it takes 12 amps to run our 1500W 12 gl water heater, not enough left to do any battery charging consecutively.

So except for running the 16KBTU airconditioner, the little Honda will run anything on the boat, just not all at once, you need to manage it.

[akopac]

So let’s step back a second and look at what we are trying to analyze.
Burning gas to make heat
Turning a generator with a combustion cycle with a maximum efficiency of 25-50% (if you want to compare to car ICE).
Inverting that DC electricity to AC, then literally shorting out the wires in a water in 6 gallons of water to heat it up.

Seriously. I think could make hot water more efficiently.

[sailorchic34]

Originally Posted by akopac

So let’s step back a second and look at what we are trying to analyze.
Burning gas to make heat
Turning a generator with a combustion cycle with a maximum efficiency of 25-50% (if you want to compare to car ICE).
Inverting that DC electricity to AC, then literally shorting out the wires in a water in 6 gallons of water to heat it up.

Seriously. I think could make hot water more efficiently.

Surprisingly most electrical sources of resistant Heating have similar efficiency. Landside power generation at the source is probably 83 percent efficienty (boiler eff, turbine eff. etc.), then you drop another 40% in distribution losses. so even a home electric water heater is only about 35% to 40% efficient based on overall system efficiency. This is approximately the same as using a generator on a boat to heat water.

Of course, generally, battery charging is also occurring at the same time hot water is being produced.

There are commercial gas fired water heaters, that approach 97% efficiency at low fire. These are not appropriate for shipboard usage.

It may not be the most efficient system. but it is surprisingly cost-effective, at least on a boat at anchor.

Could a system be designed that was more efficient. Of course. But the market is too small to recover development costs.

[Viking Sailor]

Originally Posted by sailorchic34

Surprisingly most electrical sources of resistant Heating have similar efficiency. Landside power generation at the source is probably 83 percent efficienty (boiler eff, turbine eff. etc.), then you drop another 40% in distribution losses. so even a home electric water heater is only about 35% to 40% efficient based on overall system efficiency. This is approximately the same as using a generator on a boat to heat water.

Of course, generally, battery charging is also occurring at the same time hot water is being produced.

There are commercial gas fired water heaters, that approach 97% efficiency at low fire. These are not appropriate for shipboard usage.

It may not be the most efficient system. but it is surprisingly cost-effective, at least on a boat at anchor.

Could a system be designed that was more efficient. Of course. But the market is too small to recover development costs.

SC,


How does a propane flow through water heater compare efficiency wise?


Thanks,


Paul

[a64pilot]

Efficiency is most often irrelevant, cost of fuel, availability and energy density and safety usually trump efficiency.

For example a Diesel heater may be less efficient than propane (I don’t think it is but that’s irrelevant for this example, we will say it is).
But it’s energy density is much higher, it’s much less expensive, safer to use and way more available.