RV solar with generator backup?

[PNW_Steve]

hmmmm....very interesting to have an RV/motorhome with a 24v House battery or bank...

maybe let us in on the year/make/model of your RV, and how many batteries you have, and what Volts they are, as well as their connection(series,parallel,both),
and even what Volts your Inverter/Charger(make/model) is set to charge them at....

I would also suppose that you have your solar wired at 24volts, of course...

: )

Not sure how it is relevant but here goes:

2002 Bluebird A3RE

4x L-16 batteries in series.


inverter is a Xantrex Prosine 1800/24

Charger is an Iota DLS-27-40

Solar is not 24 volt. Closer to 75 volts.

[Mike90250]

Thanks.

My want is to avoid the issue that the gent who asked the original question.

Apparently the shore power charger was causing some conflict with the charge controller.

Wired correctly, there should be no issue.

No shore power. : the SP charger has no idea if you are running the RV engine or the PV panels charging the battery.
On shore power : Do instructions state "Never start your engine while on shore power " I doubt it. Engine alternator should not cook SP , neither should PV panels.

[NCmountainsOffgrid]

I am relatively certain that the alternator won't be doing much charging while driving given that I have a 12 volt alternator and a 24 volt battery.



I am also fairly certain that the Iota DLS-40 charger will charge the batteries while I am running the generator or connected to shore power.

Thanks again.

hmmmm....very interesting to have an RV/motorhome with a 24v House battery or bank...

maybe let us in on the year/make/model of your RV, and how many batteries you have, and what Volts they are, as well as their connection(series,parallel,both),
and even what Volts your Inverter/Charger(make/model) is set to charge them at....

I would also suppose that you have your solar wired at 24volts, of course...

: )

[PNW_Steve]

My intent has been to run the generator in the morning for an hour or so to get a start on the days charging and support my coffee maker. Then let the solar take over for the rest of the day.

I would like to avoid the issues that Bala and the other gent have mentioned regarding the shore charger, run in the morning, causing issues with the solar charge controller.

[PNW_Steve]

I'm not sure your battery charging by using the generator in the a.m. is any different than most of the rest of us RV or motorhome owners.... the driving time allows the alternator to charge the house batteries, the solar provides charging when parked, at least during sun hours, and the generator is used when none of these others are available, usually the night and early a.m.

.

Thanks for the reply.

I am not sure you have a clear picture of what I am doing.

I am relatively certain that the alternator won't be doing much charging while driving given that I have a 12 volt alternator and a 24 volt battery.

I am fairly certain that solar, assuming daytime travel, will charge while I am driving.

I am also fairly certain that the Iota DLS-40 charger will charge the batteries while I am running the generator or connected to shore power.

Thanks again.

[PNW_Steve]

That's how I run my backup generator on cloudy days, a couple hours in the AM, before the sun gets going, and then if there is any sun behind clouds, it tops off the batteries. Having set points properly configured is critical.
Using a generator to hit the final 20% of charge takes hours and wastes fuel

Thanks.

My want is to avoid the issue that the gent who asked the original question.

Apparently the shore power charger was causing some conflict with the charge controller.

[Bala]

There is not really a set and forget. I know running the genset in the morning messes with my controllers but its all 12 years old so I just change things as I need to.

You should? come to understand your system and its state of charge at the end of the day and in the morning depending on what the weather was like and what your usage was.

After a while you will just know if you need to change settings, run the genset or do nothing but relax.

Like Mike said, set points are critical but may need changing a little or lots.

[Mike90250]

That's how I run my backup generator on cloudy days, a couple hours in the AM, before the sun gets going, and then if there is any sun behind clouds, it tops off the batteries. Having set points properly configured is critical.
Using a generator to hit the final 20% of charge takes hours and wastes fuel

[NCmountainsOffgrid]

I'm not sure your battery charging by using the generator in the a.m. is any different than most of the rest of us RV or motorhome owners.... the driving time allows the alternator to charge the house batteries, the solar provides charging when parked, at least during sun hours, and the generator is used when none of these others are available, usually the night and early a.m.

as for whether the house batteries get charged 'fully' every time you run the generator, I would say 'don't sweat it', especially in the early a.m. since solar will be coming into play soon enough(if you have any). Depending on your nightly usage of power, you may want your generator to run longer for more of a 'fuller' charge, but if you have an AGS(auto gen starter) module, then you can allow it to crank and run the generator during the night, if needed, such as when the batteries fall below 12.0 volts or so.

we find that having the generator run overnight is not as big of an issue, if you don't want it to - you can set your Inverter's LBCO level to 11.5 or so, and turn off the AGS - this will provide enough power during the bedtime hours, but can limit the generator starting during the overnight hours - if the Volts fall below the 11.5 setting, the inverter will simply shut off until it has 12.0 of power again, usually after you've started the generator in the morning. Your fridge will keep your good nice and cool until then - it's usually only several hours during the very early morning hours anyway. Some of us don't mind the generator running whenever it needs to, and some of us would rather not 'hear' it during sleeping hours.... : )

btw, I've never looked at our generator to 'fully' charge the batteries, since they can and may require many hours of constant run time will all the available amps going to the charger - during that time you may be limited on the other things you can do at the same time, such as air conditioners, and other heavier draw items - though your generator may be large enough and well suited to do it all, it just depends.

the quote you gave sounds like someone is concerned that their solar charge controller is not reacting correctly - that may be, but that is a solar issue, not a generator one. Solar is probably going to have a hard time ever 'fully' charging your RV's House battery bank - but it will depend on the number of batteries you have, and the sizing of the solar system - as well the aforementioned 'sun hours'. Most RVrs typically find that solar is really just a way to offset generator run time, not do away with it. For example, if it's really hot, you'll need to run your generator anyway to run your air conditioners - so solar then is a moot point since it is not really any aid while the generator is running, yet it's right in the middle of the day when the 'sun hours' are at their best - loosing the one thing you have solar for - solar power.
Solar is not really the 'dream' solution so many may think - though it certainly can have it's place in an off-grid lifestyle, especially if you can afford to have less of the 'amenities' you might normally have while on shore power or the generator.

[PNW_Steve]

Hey Everyone,

Thanks again for making such a great resource available to us. I really appreciate the mods for working to keep up the quality of information here.

I do browse some of the other boards for entertainment

I came across a question on another board that raises some questions about my RV installation.

"Basically I have to run the genny in my RV to get them to 100%. I found that running it in the morning to bring them up to 80% screws up my Victron CC by making the starting voltage the cc see's higher and shortens the absorb charge to maybe an hour or two when it should have been on absorb for 6 hours. "

I will be traveling in my RV for up to 3-4 months at a time. I will be dry camping the majority of the time.

Given the space, weight and financial limitations I have come to the conclusion that I will have to run my generator to support my larger loads. Typically a coffee maker, hair dryer and microwave.

Since my largest daily loads occur in the morning I had planned on about an hour of runtime each morning to handle the big loads and getting a head start on the days battery charging.

After reading the question above, I am questioning my plan.

Any suggestions as to how to avoid the issue that he had?

Thanks.