Full integrated rv system 4kw/6.7kw

I posted this in the LifePo4 forum asking about the ac charger, but I think doing it this way will work. However, this is my first system so I want to get input.

Does this look like a good start? Any big changes?

Is the 'Electric Generator' an inverter? (I'll assume it is)

The diagram shows both Shore power and Inverter power going into the "AC Stuff" cloud. How will it switch between the two? One suggestion for this is to use an inverter/charger with a built in transfer switch that automagicly switches to shore power when it is available. They also have the advantage of charging the LiFePO4 when plugged into shore.

560Ah is a lot for a trailer. Do you really need that much. Have you done an energy audit?
Energy Audit and system sizing tool: https://diysolarforum.com/resources/system-energy-audit-and-sizing-spread-sheet.12/

The diagram does not show fusing and wire sizes. This is an important thing to plan for from the beginning.
Fuse/breaker sizing and placement guidelines: https://diysolarforum.com/resources/fuse-and-breaker-sizing-and-placement.37/

Yes, the electric generator is a mechanical pure sine wave inverter. 1600w continuous, 2400w peak. I dont have that much ac stuff, so this should work fine.

I already have most of the right side of the diagram, so I'm trying not to replace stuff I dont have to.

I actually have no idea how the 110 circuit works. I'm missing a big peice because right now the charger only runs on shore power but the rest of the system runs on either the generator or the shore power if available. Maybe there is something fancy in the plug? It works right now though. Actually it works really well. I just need to add in the dedicated batteries and solar.

Once I figure out all of the pieces, I'll come back with a physical diagram with fuses, breakers and wire gauge. Right now I just want to make sure I understand how its suppose to work.

We dont get a lot of sun in the winter and i want to be good for a couple of days off grid. So I oversized the battery a bit. Good thing the raw cells are so cheap right now.

bgflyguy said:

Yes, the electric generator is a mechanical pure sine wave inverter.

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Interesting.... that sounds like a DC motor running an AC generator. Do you have any links to the product? It sounds very inefficient.

Oh yeah, I'm sure it's pretty bad. I luckily don't use much 110v AC. Right now, almost everything is on a switch and a 12v relay, including the inverter. This will end up being a lot more complicated than the diagram, but I'm still trying to get my head around big picture stuff.

I still haven't picked DC-DC charger, so I don't know how big to go. Are there any that are switchable? So like 10a, 20a, 40a ?

Manual for the generator:

Interesting. Why was that chosen? Did that come with the vehicle? You may want to consider replacing it sometime down the road.

It came with the vehicle, and I'll probably run it until it dies. It works well enough for me, it even ran a leaf blower once.

FilterGuy said:

Interesting. Why was that chosen? Did that come with the vehicle? You may want to consider replacing it sometime down the road.

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Is there a concern other than efficiency? Buying a new pure sine wave inverter seems expensive for an extra 10-15% efficiency for 110v ac load only.

No. primarily efficiency. Is it noisy?

I have no idea how well regulated the output is. How close to 120 Volt/60hz does it stay. (For most appliances this won't mater) Some clocks depend on the 60 hz. If done reasonably well the output should be a pretty clean sign wave.... but it would be interesting to throw a scope on it to see how clean it is.

It does make some noise, but it's mounted outside, and we don't use it too much. I found a service manual that includes some charts. It looks like it performs really bad for small loads, but for large loads does a lot better than I would have figured. I suppose this could work for a microwave or something if we wanted one. It's cool to be able to use power tools and big items as well.

Interesting contraption.

Note: A properly sized inverter and run the power tools as well. (Particularly a low frequency one).

If I was planning on running AC 24/7 I would upgrade. It's not cheap for a high quality inverter through. I opted to add another battery instead this go around.

Any thoughts on DC to DC converters?

FilterGuy said:

560Ah is a lot for a trailer. Do you really need that much. Have you done an energy audit?
Energy Audit and system sizing tool: https://diysolarforum.com/resources/system-energy-audit-and-sizing-spread-sheet.12/

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Thats not much power if you want to boondock and you don't have sun for a few days. I'm using the same 280ah cells only 12 of them for 840 ah. I would use 4 more if I had the room in the battery compartment. All charged with 4 Canadian solar 255 watt panels.

Greg