How do you use your generator?

Ok, I know there are huge differences, so maybe those folks with a similar setup as mine can answer, 43' boat with a propane galley.

We spent the night on the hook last night. The first time we tried it, the generator would start. Now it runs great. We use the inventor for microwave, sound system, Keurig, charging cell phones etc. we also use it for my wife's CPAP machine. I have the inverter set to cut out when the batteries are down to 80%. As a rough guess it looks like in this situation we would probably need to run the generator for a few hours in the morning and evening if we aren't traveling. How does this compare?

Right now it is dead calm. My wife is enjoying her second cup of morning coffee in the aft cockpit watching the rain fall. She asked me to turn off the genny because the diesel fumes are bothering her.

On the hook, I run mine a couple hours before bed, off for the night, then an hour in the morning. My inverter is too small to do all galley things, and gen is needed for hot water. It is rare for me to stay at anchor two nights in a row so main engine charges batts as I travel.

I almost never have gen on when main engine is running, but somehow I have logged almost identical hours: 2240 on main, 2100 on gen. Go figure..

I assume you have a battery monitor. If you have AGM deep cycle batteries you can run them down to 50%, then charge them up to 80%, since charging rate above this is very slow. Running the genny twice a day is a good plan, while you make breakfast, and again in late afternoon or early evening. But this is only if your batteries need charging again.

You should not be smelling diesel fumes. Where is the exhaust? Our genny exhaust is midships, and we never smell it.

My gennie exh is midships port side, and I too never smell it. I thought of running the pipe out the transom, maybe I should be glad I did not.

We're also 43' with propane. When away from shore power I usually run the generator about two hours in the morning and an hour in the evening. The first hour in the morning is to charge the batteries, then I turn the charger off and turn the hot water heater on. The charger starts off at 120 amps and if I add the water heater it's too much load.

You can set your inverter to 50-60% with good deep cycle batteries. We had an all electric full sized appliance kitchen, plus a washer and dryer and a dishwasher. (none of which the inverter ran other than the big refrigerator, microwave and coffee maker). In fair weather we ran the genset about an hour and half in the morning and two hours at evening while using all the above and it charged the inverter bank just fine. All depends on size of your battery bank, how much you've drawn it down, and the charge capacity of your inverter.

In really hot weather, it might run for all the time we were aboard the boat. Gensets are made to be used.

My batteries are sealed LA, 6 years old. Do far when I have run the genset I also use it to heat the water in the tank as well as run the fridge. With a cold hot water tank the genset is definitely working.

With LA batteries, is 80% reasonable or should I allow it to go down to 70%?

Me, I set mine to around 55% SOC. How are you calculating your % cut off?
If on the other hand, you are getting all the juice you need for as long as you need, without fussing over what items you are powering, at 80%, why change?
A few more facts would be helpful.

We run our generator anytime we're away from the dock. However, what you're describing sounds like what most people do. I would still look at the diesel issue. Perhaps just a result of how you sat vs. the wind, but shouldn't normally be a problem. I do have a very sensitive sense of smell and have smelled it from other boats when no one else did.

Dhays, did you say you only run your fridge when you run the generator? I think that's unusual. Most continue to run either on DC or via an inverter.

When on the hook we run the genny once or twice a day depending on how much sun there is and the resulting solar yield. The 120V house loads are 100% on the inverter so they run uninterrupted on battery, shore power, or generator. We also run it if we need to use the oven or do laundry, all of which are 240V. The boat has diesel heat which includes the hot water, so no generator required for hot water, and it never runs out which is really nice.

The fridge is 12v/110v so when the generator is running, we shut off the 12v to the fridge.

We get hit water from our diesel furnace as well, but I am under the impression that when the genset runs it is better to run under load, so we turn on the 110AC water heater.

I get the % figure from the Xantrex battery monitor.

45 minutes in morning. 45 minutes in afternoon. 30 more minutes if we make water for three hours 12v system).Solar panels and wind generator do an excellent job

We run coffee pot, toaster, microwave, washing machine, 9 cu feet of refrigeration/freezer. and 24/7 computer systems. Even a hair dryer.

Note we use two 105 amp inverter /chargers when generator is on.

I was told by a generator Guru that most gens have problems because they are not used enough.

We used to run our genny 2-3 hours a day when out on the hook. Then last year we installed 4 new carbon fiber batteries (Oasis Firefly batts). These AGM-style batteries can be discharged 80-100% of rated capacity without harming them. Now we run the genny a couple hours every 2 days...

We actually switched to the carbon foam batteries specifically to reduce the time running the generator. It has worked out just the way we wanted.

Nigel Calder really likes 'em, too.

Firefly Oasis Battery - Carbon Foam AGM

We too have a 43 with a propane galley. We use the inverter pretty much as you do. It serves all of our needs except for hot water. Of course we get plenty of hot water off the engine when cruising and 140A of battery charging.

On the hook with the fridge running 24/7 we typically have been running the genny 1-2 hrs in the morning and evening. This gets the batteries back to 80-85% and allows us to make enough hot water for the day. The last 15-20% of battery charging takes far too long to justify running the genny.

Starting this year, we have added a 100w solar setup which, if prelims are any indication, will really help top up the batteries and will likely reduce our genny run times. During the day we get a solid 5.5a out of it. That's only about 30ah a day, but its a major help in topping up the batteries or reducing the battery drawn down. We would have added even more solar, but don't have very good spaces for it.

When we shift to livaboard, I'm wanting to find or make room for another 100-200w.

Ken

kchace said:

Starting this year, we have added a 100w solar setup which, if prelims are any indication, will really help top up the batteries and will likely reduce our genny run times. During the day we get a solid 5.5a out of it. That's only about 30ah a day, but its a major help in topping up the batteries or reducing the battery drawn down. We would have added even more solar, but don't have very good spaces for it.

When we shift to livaboard, I'm wanting to find or make room for another 100-200w.

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Ken, Rebel here on TF has a similar boat to mine and added solar. He said it did really help keep the batteries topped off. I have some room on the Pilothouse roof that I think would be great for some solar. I don't expect it to keep me from running the genny, but I think it would reduce it.

I operate similar to kchace. I typically operate between 60-85% after day one with 2-3 hrs of gen time. It's faster to charge from 60-85% SOC than from 70-95%. I can't heat water (1300W) at the same time, either. Also, my Keurig is a high draw item for the first minute while it heats the water (1500W) so it gets solo gen time also. On shore power, it's the 30A dance...on my Honda generator, it's a 13A dance.

My previous fridge and the Nova Kool I have on order both operate 12V/120V and they switch automatically to 120V when it's present and back to 12V when the 120V source stops. You may not need to turn off the 12V CB when running the gen. What type of fridge do you have?

dhays said:

My batteries are sealed LA, 6 years old.

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Sealed as in you cannot add water? Expect issues given their age if they are indeed sealed.

Run your genny only if you can get a decent load on it, say plus 30%. Otherwise stay on inverter for normal stuff. Generally, and as said already, you can go down to 50%, but only if you know history and past performance of batteries, charger and inverter. How old in the Xantrex?

Here is the Hotter Than Hell part of the U.S.A. we run our genny for the A/C. Only other time is when the missus needs the range since that can't be run off the inverter.

We have a 4KW invertor running off a house made up of 12 deep cycle batteries. God help me when I have to replace the batteries!

dhays said:

The fridge is 12v/110v so when the generator is running, we shut off the 12v to the fridge.

We get hit water from our diesel furnace as well, but I am under the impression that when the genset runs it is better to run under load, so we turn on the 110AC water heater.

I get the % figure from the Xantrex battery monitor.

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Yes, that all makes sense. Thanks for clarifying. I often run our electric HW as well to help load the gen, though we have never run out of hot water. We also try to do laundry when charging for the same reason. I've never been able to get our generator over about 60-70% load. Maybe I'll do better when we cruise to a hot location and are running the AC.....

menzies said:

God help me when I have to replace the batteries!

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Are those AGM?

Gensets just need some load. People get way too hung up on the issue. As an example on our 25 year old Onan 20kw unit, the battery chargers alone were plenty. Ran a lot of hours with even less than that. Just had to make sure to avoid no load and proper warm up and cool down, though dozens of times doing neither proeprly didn't seem to hurt. Thing surveyed out beautifully with 8000 hours on it, about 5000 of which we were responsible for.

FlyWright said:

My previous fridge and the Nova Kool I have on order both operate 12V/120V and they switch automatically to 120V when it's present and back to 12V when the 120V source stops. You may not need to turn off the 12V CB when running the gen. What type of fridge do you have?

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Nova Kool. That is one of the manuals that I either haven't found yet, or haven't gotten around to reading. If it goes to AC when available, then I don't have to worry about turning off the DC breaker. One less thing to do.

I am on the hook, and since I have installed solar panels i run the generator for an hour every 3 days to heat the hot water. Before that 2 or 3hours a day

Most all of the problems we have with our gen sets are caused by lack of use. Because of that fact and also that I live in Fla. where it is always hot, my gen set is running when we leave the dock and is not shut off till we return to the dock. The Onan diesel gen set that I have on my 18 wheeler has over 12000 hours on it with only pm service done to it and it is still running great because it is used a lot. My Kohler on the boat only has 2000 hours on it so I am in no danger of wearing it out. Use it or lose it.

Moonfish said:

We actually switched to the carbon foam batteries specifically to reduce the time running the generator. It has worked out just the way we wanted.

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What is the weight of the Group 31 AGM Batts?

Start it before we leave the dock, and don't shut it down till we're back connected to the dock.

"then I turn the charger off and turn the hot water heater on"

Plumbing the noisemaker cooling system to the boats HW heater could relieve this hassle.

FlyWright said:

Are those AGM?

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Golf cart.

GC-110s

We just celebrated our one year anniversary cruising full time and most of that time we have been on the hook. Before leaving northern California for Mexico we installed four 335 watt solar panels from Northern Az Wind and Sun, to complement out 1800 amp hours of lifeline AGM batteries. living aboard fulltime, with 3 refrigerators (beer, wine food) and freezer, we consume way more power then most boat. But by running my 8K Northern lights for 2-3 hours daily my batteries stay above 90% and the solar is now bringing them above 100 % everyday. We have currently been off the dock for 8 weeks and given the marina availability in the middle to Northern part of the Sea of Cortez, I don't see us plugging in any time soon. The solar I installed was one of the best ideas I had before leaving the states and this year I got back 30% o my install cost in Federal Tax credits. Hope this helps somebody. Currently in Loredo Mexico I'm making about 6.5k watts per day. The best input I've seen is 83 amps inbound to the batteries.