Can you run generator under way

Monterey385 · Nov 14, 2016

Most powerboats fire up the generator before leaving the dock ... just don't switch on the battery charger ...

My 2 cents

LeslieTroyer · Nov 14, 2016

I would worry about oil starvation while heeled over, especially if the sump is mounted transverse.
I wouldn't worry about over charging the batteries

kloudie1 · Nov 14, 2016

Yup.. it is really normal for folks to run the generator while under way. A person down here can get spoiled to air conditioning under way during the heat of the summer.. and Leslie has it right, ya have to watch sustained heel angles so that the oil pump can pick up oil. If the voltage regulator(s) and battery charger are good ones and set correctly, there is no worry about overcharging.

capta · Nov 14, 2016

If the generator is a marine generator and an OEM or professional installation there is no reason not to run the gene underway. You are rarely heeled over far enough or long enough that there could be an oil problem and both the engine and gene battery chargers should be regulated. If you are worried, just don't run the gene driven battery charger. When running power boats the generators run 24/7 when the engines are on or not; no worries. Even on sportfishing boats, broadside to huge waves while fishing in the Gulfstream, I've never had any problem running a generator.
However, if this is an aftermarket or owner installation, it might be a good idea to monitor things for the first few hours as you have no idea if it is a proper installation.

Terry Cox · Nov 14, 2016

The Owners Manual for our Onan 8KW Genset recommends that heel not exceed 15 degrees while operating. Normally I run it while at anchor, but I can recall at least one instance under sail between Sydney, BC and Roche Harbor that I ran the Genset to heat water so that I could take a shower. The admiral was at the helm at the time.

Jerry Clark H356 SV Persi · Nov 15, 2016

I run mine whenever away from the dock. I have a 5kw Northern Lights with 3184 hours, so it won't hurt it. We run HVAC and all systems and stay comfortable by keeping the interior at constant temp and humidity.

Monterey385 · Nov 15, 2016

One thing to consider regarding the HVAC under sail ... make sure to take note of where your intake thru-hull is located. What you want to avoid is an angle of heel that raises the intake out of the water and runs the pump dry. Most intakes are low enough to avoid this but not always.

Stu Jackson · Nov 15, 2016

Cmp1110 said:
I have been told that it cannot be done something about over charging the batteries

If the regulator(s) is/are set to the proper voltage, you simply can't.

Here's kind of a related article on the concept:

Overcharging with Combiners or ACRs The MYTH:
http://c34.org/bbs/index.php/topic,7052.0.html

Gunni · Nov 15, 2016

When I rarely need to run the generator I will keep the boat at a low angle of heel, de-powering the sails if necessary. Same thing with motor sailing - once the boat is powered up and on heel, the engine is shut down. The only reason I would run the gen set would be on long passages where I want to recharge the batteries. We only operate HVAC at rest, otherwise everyone is properly dressed (or undressed) for conditions and temperatures.