Running on board generator

[jclays]

Has or does anyone run their onboard generator to cook a meal or run their air conditioning while underway. Most of my boat trips take several hours underway. I’d like to use my electric oven or a crock pot to cook my meal while I am underway.

 

[STB]

I run my generator any time I am underway. It starts before shorepower gets pulled and isn't turned off until afterward.

I run my air conditioner while underway. Why not?

I've cooked using electric appliances underway, also. But, of course, common sense goes a really long way w.r.t. when and what.

Why wouldn't you run the generator? Isn't thst what it's purpose?

We are talking about an "inboard" generator, nit a Honda strapped to the swim platform, right?

 

[High Wire]

Yes. Just verify adequate water flow out the exhaust at cruising speed. Some thru-hull configurations starve the generator of intake water when running.

 

[Mischief Managed]

You likely can run it no problem while underway. We have, but typically don't and just use the inverter for 120VAC stuff while underway. If we have a long passage to make, we will cook a meal in a crock pot, set in the galley sink for security, and just use the inverter to power it. The alternators on our engines have no trouble keeping up with a crock pot and it's nice to have a hot meal ready to eat when we get to an anchorage.

 

[TJM]

Absolutely run it while underway. As noted, ensure water flow. Our exhaust flow is out the port side about 3" above the water line. Underway, it was difficult to confirm flow with the splashing. We installed a low-flow water alarm on the intake side and an exhaust hose temperature over heat alarm for this exact reason. Audible alarm and lights are up on the fly bridge.

 

[STB]

Yes. Just verify adequate water flow out the exhaust at cruising speed. Some thru-hull configurations starve the generator of intake water when running.

Those configurations need fixed.

 

[Comodave]

And run enough items to load the generator properly. Don’t just run a small thing alone. So running the A/C is probably a good idea.

 

[psneeld]

I used to run my crockpot off my inverter and the 105 Amp alternator kept up fine, even with charging partially depleted house batts.

That's just for info but yes, many boats run the genset from the time the mains are started and often not shut down for days.

 

[STB]

That's just for info but yes, many boats run the genset from the time the mains are started and often not shut down for days.

As various hurricanes and major storms have passed through, my old marina often shutdown power, sometimes for days. And, sometimes, I couldn't get to the boat for days due to work. So, I'd start the generator up one weekend and shut it down the next. Maybe I'd have someone else turn it off. I'd run for 3-5 days straight. I never thought twice about it.

I'll sleep with it running if there's a reason. I should be able to leave it unattended, right?

 

[jgwinks]

I used to run my crockpot off my inverter and the 105 Amp alternator kept up fine, even with charging partially depleted house batts.

That's just for info but yes, many boats run the genset from the time the mains are started and often not shut down for days.

And be careful of there's no hour meter on the genset. It could have a LOT more hours than the mains.

 

[jgwinks]

A lot of boats are set up to run the gen whenever not plugged in, small or no inverter, etc. Mine was when I bought it but I installed a big inverter charger and more batteries so I don't need to run it all the time. I also converted to propane cooking. The goal was lower fuel consumption and noise. I especially don't want it running at anchor unless my batteries are low. Coming from sailboats I don't like engine noise. If I need heat or AC while underway I will run it though.

 

[STB]

I have a big inverter, but run my generator anytime I'm underway, anyway. I figure there is no way I can get water up the exhaust while itnis running, it keeps it exercised, and why no

 

[JohnP]

When hot, humid and no see umms or green heads are biting it is great to run the genny and the ac while steering at the lower station. Usually don't need it for heat. The engines do a good job warming the interior in the temps we boat in.. Answer is yes running the genny under way is no problem.

 

[jgwinks]

As stated earlier, if the generator's cooling system is such that it can't get good water flow when the boat is running max speed, that needs to be fixed. But DON'T put a scoop shaped strainer on it facing forward. That could force water up into the system when the gen is not running and hydrolock the engine. Forward facing scoops are ok on powerboat main engines but not on anything else that might not be running when the boat is underway. They look like they should face forward but that may not be the case.

 

[Mako]

I would only run my generators when underway because they were as freakin loud as my 2 Jimmies! I hated both the Onan and Westerbeke. Nasty.


However as mentioned earlier, you can power your inverter with a large frame alternator when underway, if that provides enough power and you're good at energy management. Otherwise I hope you have a good sound box around your genset.


When anchored or drifting I would run off my 3kW transformer inverter and set of eight 8D's. Oh, didn't have air conditioning but did have a fully electric galley, domestic fridge, deep freeze, etc.

 

[Mambo42]

I only run the generator on days without sun, i.o.w. with overcast. I have enough battery to power everything, but if we have a storm (usually also with overcast) I will run the generator when underway to make sure I keep power to the stabilizers and when we are anchoring. I want to be sure the batteries don't get drained if I have to re-anchor twice or three times or use the thrusters a lot.
Sleeping with the generator on I will not do. If it is running I will stay awake and if I need to sleep the generator will be switched off. Probably not necessary, but just a precaution.

 

[Mako]

BTW my big boat had electric heating and I lived in Seattle (Lake Union). Boy that was a big mistake, never to be made again. A little generator may only use 1/2 gph but in a day's time that's about $50 or more in cost.

 

[Lepke]

My boat came with 2 generators. PO ran 1 24/7. Both had glazed cylinders from running with light loads. After rebuilds, I put in a 48v inverter that outputs 240/120, 48v alts on my mains, and a battery bank that allows me to run off the inverter for 3 days. The 48v alternators keep the battery bank up while running so only rarely do I run the generators. I don't need them when running and now only run one every other day to charge, make water, and do laundry. Sometimes done under weigh w/o the generator. Everything runs thru the inverter. So there's no transition from shore power. When the power goes off the inverter takes the load. When power comes back on, either shore power or generator, the inverter charges the bank. Wiring was simple and running is simple.

 

[Mako]

Are you running off of good ole 8D's or do you have a lithium bank? Also what size inverter?

 

[twistedtree]

My boat came with 2 generators. PO ran 1 24/7. Both had glazed cylinders from running with light loads. After rebuilds, I put in a 48v inverter that outputs 240/120, 48v alts on my mains, and a battery bank that allows me to run off the inverter for 3 days. The 48v alternators keep the battery bank up while running so only rarely do I run the generators. I don't need them when running and now only run one every other day to charge, make water, and do laundry. Sometimes done under weigh w/o the generator. Everything runs thru the inverter. So there's no transition from shore power. When the power goes off the inverter takes the load. When power comes back on, either shore power or generator, the inverter charges the bank. Wiring was simple and running is simple.

This is the direction that power systems are all going, and where "hybrid" diesel electric works really well on a boat. I'm envious of your 48V system.

 

[twistedtree]

Are you running off of good ole 8D's or do you have a lithium bank? Also what size inverter?

And what inverter are you using?

 

[O C Diver]

I run the generator underway for air conditioning, but generally little else as the alternator and inverter equal about a 3 KW generator.

Ted

 

[ranger58sb]

We run the inboard generator underway when we need either AC or heat. Haven't cooked underway, other than some quick shots of microwave (with either generator or inverter), but we could, easily enough. Crockpot or Instant Pot resting in the sink...

Interesting comment about Onan, above. We can't really hear ours...

-Chris

 

[Adulikjr]

Run your generator with a load

I'm amazed how many people wont leave the dock without first starting their generator. I ask the question why. Sure if your running your AC or cooking on an electric stove fine. But your generator should have a 75% load on it all of the time for optimal life. If your generator is not under load your are hurting the engine. Same applies to your engines, they need to be run under load.

 

[dutch-barge]

Why run a generator...extra noise, extra maintenance, extra fuel.
why not use the inverter.......

 

[Circumnavigator]

Fintry needs 120/240VAC while underway for steering, lights, and hotel loads, so we ran one or the other of two 9kW Northern Lights whenever underway, including the Atlantic Crossing. No problem -- marine generators are built to run continuously.



Jim


Sweetwater - Swan 57 sloop - circumnavigated 1995-98
Fintry - x Royal Navy Fleet Tender 2003-22 20k miles including x-Atlantic The Fleet Tender Fintry
Morning Light -- Webbers Cove 42 trawler 2021- 23
Going back to sailing now that Morning Light is sold.

 

[Lepke]

And what inverter are you using?

I use 8d batteries. Too many stories about battery fires for me to use lithium.
My inverter is a Magnum MS-PAE 48v. You can gang up to 4 for 17.6kw. Mine is on 24/7. When I disconnect shore power, it switches to battery automatically. if I start a generator it switches to that. If running on inverter and the batteries get low, it starts a generator. If I connect to shore power, it starts charging. The only hard part is maintaining all those 8d batteries.


The best generator is a Detroit 2-71/20kw. Uses less fuel than my Onan 14kw. It runs at 12oo rpm and isn't plagued by glazed cylinders like smaller, faster running engines are. They last for decades. I don't remember ever rebuilding one.

 

[dutch-barge]

Why run a generator...extra noise, extra maintenance, extra fuel.
why not use the inverter.......

2 X 24/3KV Victron. 10 year warranty

20 KW Li batteries from eco-lithium. same price as gel batteries

Mistubishi AC, Induction cooking , 1800 W solar, 90 amp 24V alternator

Kabola Diesel heating (radiators and forced air)

 

[ranger58sb]

I'm amazed how many people wont leave the dock without first starting their generator. I ask the question why.

Why run a generator...extra noise, extra maintenance, extra fuel.
why not use the inverter.......

As built, AC-only household fridge and freezer... and what inverter would that be?

And on a boat that spent much (most?) of it's life in Florida, so POs would have routinely been using generator for the five ACs.

Modified, since then, with our inverter installation... on the boat that didn't have one for its first 15 years.

-Chris

 

[psneeld]

The Li Batts used in RVs and Boats are not the same chemistry as the ones in phones, computers and e Bikes...... and don't have the same fire risks.