Alan asked me a question about the Honda EU2000i specs and it seems like a good chance to talk a little more techy power stuff:

Question:
Can you clarify your Honda 2000 output .
The Manufacturer specs on this unit is :
DC output=12v,96watts(8A)
AC output=120V,2000watts MAX
(16.7A)1600watts RATED
(13.3A) Continuous
Are you putting the 75A into your system by running the Honda for @5 hours ,120V/13.3A ? Is the 13.3A powering your washing machine+three laptops+freezer ? Or is the combined total electrical "draw" of those in excess of the 13.3A ?
Thanks

Answer:
Those above specs are correct.
The Honda will power a 75A-DC battery charger continually and will do it for right at 5 hours on a tank of gas, which is 1.0 gallon. So if my batteries are discharged enough (which they typically are) then I can run the 75A-DC battery charger and actually put 75A-DC into my battery bank for at least an hour before the charger starts dropping off the charge current Amps as the voltage of the batteries come up. The 75A-DC battery charger uses just about all of the Honda's steady state 13.3Amps-AC, but for a 30 minute period you can get 16.7A-AC out of the Honda before it automatically revs down to it's steady state load of 13.3A-AC or trips the breaker.

The way my boat's power system is set-up, I can run all of my AC loads through my 3000W inverter/150A-DC Xantrex battery combination inverter/charger OR I can switch to either the shore power (IE Honda Gen) or my 8KW diesel genset (which I rarely use). When I was writing that blog post and referencing running the washing machine, freezer, fridge, battery charger, and 3 laptop computers running off of the Honda I was running all of those appliances through the power inverter, that at the same time was taking 75A-DC and putting it back into the battery bank from the Honda. So in reality, 75A-DC was going in, but 32A-DC was going out when the washing machine was on spin cycle, 3A-DC was going out for each laptop, 3A-DC was going out for the freezer and then 6A-DC was going out for the refrigerator. Do the math and add up the ins and outs and I was getting a net into the battery bank of lets say 25A-DC. So yes, the Honda was "powering" all of those devices, and still putting power into the batteries.

Now I could have switched a switch and bypassed the whole inverter and ran all of the AC loads right off of the Honda, but I figure I might as well be getting some extra power while the Honda is running into the batteries. In reality the refrigerator and freezer cycle off and on and the washing machine uses 1/3 the amps when it's not in spin mode, so during those times more of the Honda's power is going into the battery banks.

A great feature on the Honda is the Eco throttle mode, which will rev up and down the engine based on the load demand. The Honda will only run 4-5 hours on a tank of gas at heavy loads, but 8 to 10 on lighter loads. The way I like to run things is to work it hard for a shorter amount of time and make as much power as I can and then shut it down and put our sunbrella cover over it. This way it's less time to deal with it running up on deck.

When it comes to making water, I'm using about all the Honda can put out with the 13.1A-AC load of the water maker. But I've played around and found I can take 2 more AC amps from the Honda while making water and use that power to send to my battery charger (hey every little Amp helps). My battery charger lets me tell it how many amps from shore power (aka the Honda) to take. If I dial up above 4A-AC while making water, it trips off.

The Amp discussion is sometimes hard to follow because an AH (or Amp*Hour) is what you care about on a boat rather than just an Amp reading. As a crude and simple example, a 800AH battery bank can put out 800A for 1 hour, 200A for 4 hours, 100A for 8 hours, etc. Now the real world doesn't quite work that way, but when I run my 75A-DC battery charger for 1 hour, I can put 75AH back into the battery bank. To add to the confusion, throw into this the idea that we are talking AC Amps at 120 volts on the shore power (Honda) side but DC Amps at 12V on the battery side. The confusion can go on and on.

A 10A AC 120V load is about a 120A DC 12v load...move the decimal over and add 20% to go from AC-120v to DC-12v. This gets people all the time because they see their 3A AC-120V appliance and think it will be no problem to run if through their inverter while on a boat. Well that 3A-120AC appliance will turn into roughly a 36A-12V DC load and suck their battery bank dry in no time at all!

This whole 120v-AC versus 12v-DC issue is why most people don't have enough surface area on their roof-tops to even dream about covering the average homes power usage with 12v Solar (yes I know most home system are 24v or 36V DC..but the point remains). So what's the take home message of all these words and figures? Well that's simple, you won't have enough power aboard your boat and you can either be one of two cruisers: One with a Honda or one that wants one. Well I guess there really is a 3rd type of cruiser, but you can call them campers and to borrow a line from Seinfield, "not that there is anything wrong with that", but we wouldn't be on our 4th year of cruising as campers.

While I'm on the Honda rant....lets talk about gas. People say, "I don't want to carry all that gas for a Honda, heck that's dangerous on a boat, and my dock neighbor "expert" says I will blow myself up". Here's the reality. 99% of cruisers carry gas aboard their boat, up on deck in plastic fuel cans, for their outboard dingy motors. So rather than carrying one 5 gallon jug of gas, now you carry two. Is that twice as dangerous, well you decide, but the gas argument against the Honda seems bogus to me given the reality of already carrying a gas bomb on deck.

How about the noise argument, isn't a Honda noisy, smelly and spews out deadly carbon dioxide that will kill you, your crew and the world? First off, if my Honda running at anchor bothers you, then you anchored too close to me, sorry, but that's just the truth. I've gotten in the dingy and went around the anchorage while mine and other Honda's were running and unless you run the Honda at 2AM, then you will hear more noise from the cruiser dingy motors and panga fishermen zipping around the anchorage than form a Honda. Sure it's a combustion engine, and it creates exhaust, but try motoring downwind smelling your own diesel engine exhaust before worrying about a Honda. Remember, you can place it strategically on deck to direct the fumes overboard.

Here's the truth about it folks, some cruisers don't like the Honda not because the noise bothers them at anchor or they smell the toxic exhaust. They don't like them for the same reason the cranky neighbor doesn't like the sound of your kids playing in the back yard on the swing-set or in the back yard pool. Then there are the sailing purists that write books and preach about cruising with no batteries, no refrigeration, and no fun (ok, I threw in the fun part), but honestly, this isn't 1970 anymore. But when these folks see a Honda running on deck, it drives them crazy because we are supporting "Big Oil" or God forbid the "evil 1%" by burning fossil fuels.
Don't make the mistake to think that complainers, looking for something to be unhappy about don't go cruising, ha ha ah...let me tell you, they are out here also!

I won't name names, but I know a cruiser who uses his Honda as a way to drive off cruises with SAS (Separation Anxiety Syndrome). When he sees them circling his boat looking like they are going to anchor too close, he points his Honda right at them and fires it up to supply power to their boom-box, preloaded with Ice Baby Rap Music. Come to think of it, that could be reason enough to have a Honda, beach party blender benefits aside.

[Editors Note: I was feeling in a great writing mood today, as can be seen by my long ramble to a simple question. I think my Santiago Flea Market Carnita Taco recovered me from my writing funk that fell over me while in the States. I'm back and it feels good!]