Best time to run generator

[TayaraTravel]

Now that I have semi-civilized the Onan with a resonator and vibration mount, I wonder if certain times of the day are better for using it, in order to minimize both propane consumption and noise.

Suppose: while boondocking, solar charging fails to completely keep up with electric consumption over a 24 hour cycle.

Would it be better to
A) run the Onan in early morning, when the batteries have reached their max state of discharge over the cycle. Use the Onan to complete bulk charging, then shut it off and let the solar complete absorption phase.
OR
B) run the Onan late in the evening to make up for battery drain between late afternoon and night?

Presumably A is better use of propane and run time, because the generator is pumping more charge in a shorter period of time. (Let's ignore the social impact of the noise on other campers.)

[Protagonist]

The best time to run it is when you need more power than your batteries can provide— or when you need to run things the batteries won't power at all.

For example, if you want to use the microwave to prepare dinner, then dinnertime is the best time to run the generator to charge the batteries, too. Because you can't run the microwave off your batteries, and if you're going to run the generator to power the microwave anyway, might as well also put it to work charging the batteries.

In the summertime, the hottest part of the day, when you're most likely to need to run the air conditioner to cool down the van, is also the best time to charge the batteries.

Otherwise, during sporting events when everyone else is inside their own RVs watching the game is a good time to run the generator. Especially if you're not a sports fan or you don't mind the generator's noise when you're trying to watch the game!

And when it rains is a good time to run the generator, because you're not getting any solar charging AND everyone else is inside their own RVs staying dry.

And for when none of those cases apply? Then shortly after dark, when you're not getting any more solar charging, but before
"quiet hours" noise restrictions go into effect for the night.

In other words, there is no one single best time, but plenty of best times depending on where you are and what everyone else is doing.

[uncle_bob]

Hi

The answer may well be, run it several times a day rather than run it at one magic time. Six hours of run time probably will do you more good as three two hour long bursts than as one single long blast. Two hours in the morning to recharge after the night, two hours at lunch and two at dinner maybe. Your battery depth of discharge will be reduced (which is a good thing). The loads you have at meal times will be taken up by the generator. Yes, this sort of *assumes* you are out "doing stuff" most of the day and not pulling max power at 10AM and 2PM with no use in-between ...

Bob

[ROBERT CROSS]

We do 'A'...

Usually during breakfast prep & cleanup.
We conserve relentlessly...1.5hr a day usually keeps things going.

Bob

[OTRA15]

Even while boondocking, it is nice to be considerate of any neighbors. As in campgrounds, when a few folks run their gens at the same time, there is harmony of sorts. We aim to top off around 9 AM and 5 PM, as needed, for an hour or so.

[amirm]

We don't do either. Instead, we get in the car and go for a drive! At > 100 amps coming from engine alternator, you can charge your batteries far faster than the generator can. Because of this much greater charge capacity, I also use the engine for 10 to 15 minutes to bring up the battery charger in the morning if we are not going anywhere soon. At > 4X the charge current of the generator+inverter/charger, that is like one hour of running the generator.

With our microwave now running on Lithium batteries, our generator gets very little use.

[uncle_bob]

Originally Posted by amirm

We don't do either. Instead, we get in the car and go for a drive! At > 100 amps coming from engine alternator, you can charge your batteries far faster than the generator can. Because of this much greater charge capacity, I also use the engine for 10 to 15 minutes to bring up the battery charger in the morning if we are not going anywhere soon. At > 4X the charge current of the generator+inverter/charger, that is like one hour of running the generator.

With our microwave now running on Lithium batteries, our generator gets very little use.

Hi

If you are charging through a normal 7 pin connector, you will not get more than 40A before it melts. Given the wire sizes used, delivering a useful charge current above 20A is rare indeed.

Bob

[Mollysdad]

I ran it when I needed it.
Morning when I made coffee and showered, maybe caught the news on TV.
Then in the evening to make supper (or dinner in some parts) and watch a little TV.

I was gone during the day and I didn't need it as the night cooled.

[OTRA15]

Bob, the post you quoted #6 is from an AI owner, not a trailer, as is the OP here IMO.

Originally Posted by uncle_bob

Hi

If you are charging through a normal 7 pin connector, you will not get more than 40A before it melts. Given the wire sizes used, delivering a useful charge current above 20A is rare indeed.

Bob

[amirm]

Originally Posted by uncle_bob

Hi

If you are charging through a normal 7 pin connector, you will not get more than 40A before it melts. Given the wire sizes used, delivering a useful charge current above 20A is rare indeed.

Bob

As Otra mentioned, we are talking Airstream Interstate here. I think the gauge of the wire going from front to back is 2/0. WHen I measured it, it would overflow my 100 amp clamp meter on and off. So my number are real as is my experience with it.

With my Lithium re-wire, I pull nearly 120 amps over the same wire now and again able to quickly charge my 300 amp/hour cells without the need for generator.

[OTRA15]

Thanks for the clarification.

Do you have your own thread for your AI lithium mods? I only found posts like these:

[click on arrows in quotes to go to those posts]

Originally Posted by amirm

That's good to know. Since the stock AGM setup also pulls over 100 amps and there are no reports of premature alternator damage, it gives me hope that this setup works as well too.

When I did my conversion, my AI was very new and I sure did not want to turn it into a brick by experimenting.

Your experience gives me hope that it might work without having a charger in between.

What is the system for stopping back charge of the chassis battery from lithiums? Is the Victron isolator in there?

Originally Posted by amirm

The battery upgrade is mandatory in my book as the system as is, is just not usable. In our area solar is not as useful so I am not big on that. I use the engine or generator if I need to charge my batteries.

Thanks,

Peter

[Titus]

OP: What vibration mount did you use and how did you install it? I have installed the resonator, but additional quieting would not be a bad thing.

[amirm]

Originally Posted by OTRA15

Thanks for the clarification.

Do you have your own thread for your AI lithium mods? I only found posts like these:

No I don't. I am overdue to make one.