What is a genny required for?

[mjfink]

I'm looking at cruisers in the 26-30' range (Four Winns 288, SeaRay 260/280, etc) and see some with and some without Genset. I'm assuming that all boats in this class have an inverter, so, except for the obvious ("run something all night without running an engine) what else requires a Genset to use away from shore power?

For example, can I run AC on a boat like this off an inverter? What about the microwave? If I'm going for quick jaunts, any reason I can't just get some extra deep cycle batteries and forgo the expense of having another engine to worry about?

My primary use of 110V power would be the microwave/TV and perhaps AC.

Any experience/guidance offered will be much appreciated ("I have a 28' cruiser, and would be very unhappy if I didn't have a genny because .....").

Thanks!

 

[Tahorover]

Re: What is a genny required for?

No way to run A/C off of an inverter.

 

[cpubud]

Re: What is a genny required for?

microwave pulls too much power to us off an inverter as well

 

[smokeonthewater]

Re: What is a genny required for?

You could run AC or a micro off of an inverter but your time is really limited.... ex if the A/C or MW draws 15 amps at 110 v ac then you are looking at 1650 watts. 1650 watts at 12 v comes to 137.5 amps 3 big deep cell batts with 105 amp capacity would run that load for 2.29 hours under ideal conditions if you had 100% efficiency (which you wouldn't) and if the batts could handle the constant load of 45.83 amps.

If you had the 3 deep cycle batts the micro would be fine but the AC not so much

OH and you obviously would need a big inverter and no not all cruisers have them


As for tv, get a 12v tv

 

[cyclops2]

Re: What is a genny required for?

AC on boats should have a AC compressor on the main engine. With a car clutch setup to engage or disengage. Some cars have 3 to 5 tons at 3000 rpms. ChecK out the big car setups for a boat. A few longer hoses & fans. Life is good.

If you need AC the engine noise is no problem.
Stopped. CO2 & CO will & does kill & basket case, people each year.

I go naked & fan on high. Doable.
Daytime. Main engine AC compressor for sun, drinks & moving around.

 

[arks]

Re: What is a genny required for?

My 34 footer has a genny but no inverter.
IMO if you have the choice, get a boat with an installed marine genset. It's just easier.

If you'll ever want to run A/C away from the dock, you need an onboard generator. Period.
The other accessories (including a small microwave) can be managed with an inverter and battery bank.
Another big PLUS for a genset- it can re-charge your house batteries when coupled to an onboard charger. An inverter won't do that.....

 

[smokeonthewater]

Re: What is a genny required for?

running a/c from the main engine doesn't work well for sleeping on the hook.

CO detector and proper genny install are a must.

 

[kmarine]

Re: What is a genny required for?

The only thing I run without my generator on is a refrigerator from a house battery. The question is do you plan to anchor and beach for extended periods? (over 3 hours) If so a generator is quite usefull. If you plan to be a harbor boater tho takes an occasional ride with the engines running when out of the harbor, then it is probably not worth the extra weight and additional maintenance, as half the generators I work on are from sitting not being used as the fuel rots in the carburator.

 

[Don S]

Re: What is a genny required for?

Not sure where some of you guys are getting your information, but I have never seen nor heard of a boat using automotive air conditioning, and inverters are used on microwaves all the time, and inverters are not standard equipment on boats.
There are marine air conditioners, and they do need generators, not inverters. Microwave ovens work if you have a large enough invert and enough batteries. They only run for minutes, not hours on end.

 

[smokeonthewater]

Re: What is a genny required for?

Don, there actually are companies that sell engine driven marine AC systems but they are obviously not well suited for stationary use

 

[cyclops2]

Re: What is a genny required for?

Not sure all marinas will allow sweet "Diesel perfume" while tied up in port next to other boats. The CO & CO2 alarms will keep us all up.

 

[smokeonthewater]

Re: What is a genny required for?

Here is a cool source for basic battery info
below are a few examples of engine driven A/C
ocean breeze
nauticool
seafrost

 

[smokeonthewater]

Re: What is a genny required for?

Not sure all marinas will allow sweet "Diesel perfume" while tied up in port next to other boats. The CO & CO2 alarms will keep us all up.

In the marina you use shore power... the genny is for the few boats that actually LEAVE the marina

 

[r.j.dawg]

Re: What is a genny required for?

Not sure where some of you guys are getting your information, but I have never seen nor heard of a boat using automotive air conditioning, and inverters are used on microwaves all the time, and inverters are not standard equipment on boats.
There are marine air conditioners, and they do need generators, not inverters. Microwave ovens work if you have a large enough invert and enough batteries. They only run for minutes, not hours on end.

+1 - The Magnetron in a microwave is considered a high voltage device. The high-voltage components accomplish this by stepping up AC line voltage to high voltage, which is then changed to an even higher DC voltage. It will suck your batteries dry just heating up a cup of water. If you have a huge house battery bank, like in a 50 footer, you might be able to cook a microwave dinner. Marine gennies are the way to go. Forget the inverters.

 

[alexr254]

Re: What is a genny required for?

I would love to see some links for possible genny choices too

I'm looking at my options for my 26' FC.

 

[H20Rat]

Re: What is a genny required for?

+1 - The Magnetron in a microwave is considered a high voltage device. The high-voltage components accomplish this by stepping up AC line voltage to high voltage, which is then changed to an even higher DC voltage. It will suck your batteries dry just heating up a cup of water. If you have a huge house battery bank, like in a 50 footer, you might be able to cook a microwave dinner. Marine gennies are the way to go. Forget the inverters.

I've got a 2000 watt inverter in my RV, and it has no problem powering a microwave. yes, a microwave is a magnetron, etc, etc.. Luckily the inverter doesn't care, or at least didn't the dozen or so times I used it last summer. It sees a 1200 watt mostly inductive load with a relatively small start up current. A CFL light bulb is also a high voltage device, and draws barely any power...

Although its on land, my RV is set up similar... Two relatively normal size house batteries, 2000 watt inverter, AND a generator. I camp in areas where I prefer not using the genny, so I use the inverter as much as possible. I've never had a problem using the microwave occasionally to heat up breakfast, coffee, and some leftovers, as well as powering everything else, for a day of use. The inverter will NOT power the AC though, the startup load is far too high.

 

[smokeonthewater]

Re: What is a genny required for?

how the micro works has no bearing on the issue.... It plugs into a 15 amp outlet with a 15 amp breaker and does not draw any more than that. As I stated above that is 137.5 amps (or less) at 12VDC. You can't run that for long on one batt but with three you get a couple hours... I don't currently have an inverter on my cruiser so I have to run the genny just to heat up a cold slice of pizza or nuke a hotdawg. I plan on adding an inverter and it will run the micro for my use just fine BUT the genny is IMHO a must have.

 

[Don S]

Re: What is a genny required for?

Don, there actually are companies that sell engine driven marine AC systems but they are obviously not well suited for stationary use

I know there are marine setups, what I was referring to is the remarks about looking at big car setups for air conditioning for a boat. But it doesn't do anything if you shut the engines off. Nor do they work well at idle. That is why there are generators, and marine AC units, shore power for the dock and such.

I also lived aboard for 12 years, 4 with a gen set 38' power boat, and 8 years on a 41' sail boat with an inverter. I know for a fact that microwaves work on inverters, so does a Mister Coffee.

 

[smokeonthewater]

Re: What is a genny required for?

gotcha.... we agree on all points then

I am constantly amazed at the things some folks will adamantly state as fact without any real knowledge on the subject. I especially get a kick out of folks saying something can't be done that others do on a daily basis.

 

[Don S]

Re: What is a genny required for?

I am constantly amazed at the things some folks will adamantly state as fact without any real knowledge on the subject. I especially get a kick out of folks saying something can't be done that others do on a daily basis.

Unfortunately, it happens all the time on forums.