What Inverter set up for a F44 Motor Yacht?? Genset is over

jwrape · Post by **jwrape** » Wed Apr 22, 2009 6:50 am

Well I have been working on my GenSet for over a season now and going into my second season. The GenSet is old, smokes and now I can't seem to get it to run at all. I am tired of it and want to consider a inverter and a battery bank.

Onboard we have a Firdge, Ice Maker, 3 TV's, Microwave, Blinder, and of course the A/C units...

What size Inverter would I need and how many batteries of what kind?

aaronbocknek · Post by **aaronbocknek** » Wed Apr 22, 2009 7:04 am

i know this is something that you might not want the hear, but i don't think there is an inverter or battery bank large enough to run all that ac equipment. you might want to consider a new genset. i know they are expensive, but i don't know if you can run all that on an inverter. with the market being what it is, maybe a kohler or westerbeke dealer might be able to make you a deal. i know the dealers here in baltimore are anxious to move products and i spoke with a westerbeke dealer at the baltimore boat show in january that said he would sell and install a small westerbeke in my f-32 for 5 grand. if i had the skekels, i'd do it in a minute.
but, that's just my opinion.

jwrape · Post by **jwrape** » Wed Apr 22, 2009 7:53 am

aaronbocknek wrote:i know this is something that you might not want the hear, but i don't think there is an inverter or battery bank large enough to run all that ac equipment. you might want to consider a new genset. i know they are expensive, but i don't know if you can run all that on an inverter. with the market being what it is, maybe a kohler or westerbeke dealer might be able to make you a deal. i know the dealers here in baltimore are anxious to move products and i spoke with a westerbeke dealer at the baltimore boat show in january that said he would sell and install a small westerbeke in my f-32 for 5 grand. if i had the skekels, i'd do it in a minute.
but, that's just my opinion.

Well, not only do I not have the $$$ for that, i would have to cut my floor to re-open the motor hatches to pull the old one as well as remove my head liner and exterior hatch to pull it through the ceiling of the salon...
Getting another GenSet in there is just not something I really want to do if I can at all help it.

I had heard that a boat of my size would run on a 3000watt inverter.... Am I wrong?

It would be MUCH easier to disassemble the GenSet and replace it with an inverter and battery bank.... I usually don't stay out all night, usually just stay out from 11am to 6-7pm during the day and come back and dock at night.

Please tell me there is an inverer option, there's gotta be something.

aaronbocknek · Post by **aaronbocknek** » Wed Apr 22, 2009 8:16 am

jw.... you might want to do a google search for a large inverter to run the electric equipment on the boat. to be honest, i am clueless when it comes to the whole inverter stuff. i have a small one on my f-32 but i always run the genset when i go out. they were meant to run and even with a small load on it, it keeps it happy and while underway, the water from the seacock is not 'forced' into the impeller.
let me know how the inverter option pans out as i am curious.
aaron

jwrape · Post by **jwrape** » Wed Apr 22, 2009 8:32 am

aaronbocknek wrote:jw.... you might want to do a google search for a large inverter to run the electric equipment on the boat. to be honest, i am clueless when it comes to the whole inverter stuff. i have a small one on my f-32 but i always run the genset when i go out. they were meant to run and even with a small load on it, it keeps it happy and while underway, the water from the seacock is not 'forced' into the impeller.
let me know how the inverter option pans out as i am curious.
aaron

Ok.... I will continue to research it.

LandVF36 · Post by **LandVF36** » Wed Apr 22, 2009 9:11 am

Every device that you want to run has a UL tag on the back. It will show the power requirements in Watts or Amps. If it show Amps, multiple that buy 120 to get Watts. then add it all up.

A microwave, even a small one, is probably 700 to 1000 Watts. Your fridge is likely half that. Don't forget your stove and water heater if they are electric. When you have a total, add about 20 percent for a safety factor, then pick a unit that states it will generate a pure sign wave. the cheap ones don't and you will shorten the life of most appliances.

The manufacturer you sellect will have a chart for sizing the battery bank to match the unit you buy for the hours you want to keep things running.

farfrompuken · Post by **farfrompuken** » Wed Apr 22, 2009 6:10 pm

get a hoda portable and put it out on your swim platform when you are out and you can probably run everything you have .i have a honda 2000eu

farfrompuken · Post by **farfrompuken** » Wed Apr 22, 2009 6:13 pm

get a hoda portable and put it out on your swim platform when you are out and you can probably run everything you have .i have a honda 2000eu

farfrompuken · Post by **farfrompuken** » Wed Apr 22, 2009 6:14 pm

get a honda portable and put it out on your swim platform when you are out and you can probably run everything you have .i have a honda 2000eu

ready123 · Post by **ready123** » Wed Apr 22, 2009 7:35 pm

I doubt a Honda 2000 can run even one of his AC units.... of course if he were to use the three you showed above.

ltbrett · Post by **ltbrett** » Thu Apr 23, 2009 12:02 am

You will not be able to run your air conditioning on an inverter. A 16k btu a/c draws about 15A at 120vac, and needs almost three times that to start. Convert that to dc and you're looking at a constant draw of 150A, or about three group 31 batteries per hour. The rest of your gear could be run on a properly sized inverter and battery bank. Do the math first--you might find it pretty expensive to expand your house bank enough.

Brett

jwrape · Post by **jwrape** » Thu Apr 23, 2009 6:29 am

Yea, I've decided to get the Onan technician to come out and fix the Genny.
Got a appointment for May 5th

RWS · Post by **RWS** » Thu Apr 23, 2009 6:49 am

If you run ANY kind of gas genny GET A CARBON MONOXIDE DETECTOR for each seperate cabin on your boat.

People have been KILLED.

DON'T BE ANOTHER STATISTIC.

RWS

jwrape · Post by **jwrape** » Thu Apr 23, 2009 6:50 am

RWS wrote:If you run ANY kind of gas genny GET A CARBON MONOXIDE DETECTOR for each seperate cabin on your boat.

People have been KILLED.

DON'T BE ANOTHER STATISTIC.

RWS

Already got em'.

randyp · Post by **randyp** » Thu Apr 23, 2009 8:56 am

Per my reply on your other post I'm glad you're getting the Onan guy to take a look at the genny. I too have the Honda 2000 and it works fine for my boat, but I'm not running A/C or any huge electrical appliances, not even a MVave.

Use the advice that's been given. If you want to get an inverter to run your AC appliances and Air Cond when away from the dock you're going to need a lot more battery capacity. Look for deep cycle batteries not dual purpose. Look for either reserve or amp hour ratings, not cranking amps. The higher the reserve and/or amp hour rating the better. And if amps and watts have you confused here's a simple formula. Think of "WAVE" - Watts equal amps times volts. So, for example, a 12 volt light with a 12 watt lamp would require 1 amp to run it. (Amps = watts/volts).

Here's a design rule from West Marine: "If you know the load that is placed on the inverter in watts (your fridge, A/C, etc) you can divide by 10 to find the DC load in amps. If an inverter is going to run a 500-watt load it will draw around 50 amps DC. Keep two things in mind: 500 watts is not very much power and 50 amps (DC) is a heck of a lot of DC current to use. Not many DC loads on boats 40' and under draw 50 amps or more for more than a few minutes. Therefore an inverter frequently becomes the largest DC load on most boats, and may require substantiall changes in battery capacity and wiring of the boat in which it is installed. "

My feeling is that you don't have enough battery capacity to run anything close to what you need in an inverter, and the extra battery capacity, possible re-wiring, etc is going to cost you a lot more than getting the genny fixed, or replaced.

If you're using the boat off the hook for day anchorages and the occasional overnight then going for an inverter is really never going to be worth the expense.

My recommendation is to focus on the genset and boosting your battery bank capacity - have one starting battery EACH for each each engine, not wired in parallel, like you currently have. Have TWO house bank deep cycles wired in parallel, and one dedicated start battery for the genny. Be sure these are wired to switches. If you don't feel confident doing this yourself have a pro do it for you. No sense burning up the boat to save a few bucks.