GreyHawk 29MV Solar Install "PRE PLANNING"

[Captain Morgan]

That's right - PRE PLAN ING

I can buy the banks of batteries, I can buy a 3,000w pure sinewave inverter, and I can buy 8 big honkin solar panels, but I still need to integrate this in to the 29MV specific house architecture.

Surely this will not be as easy as "Hey Joe, just take out the inverter you have now and wire the new one in" as far of integration is concerned.

So for the sake of this thread not getting derailed and going in to the twilight zone on a hundred sub topics, just imagine that 1) you have a 29MV and 2) that you have a garage full of parts. You want to map out the integration in to the existing house infrastructure . . . what specific areas are you focused on?

This is not about batteries and solar panels. This is not about what parts to buy. This is the sum voice of experience from people who have done solar installations and integrated upgrades in to their own infrastructure.

Example #1: the current single house battery is charged both from the vehicle alternator and the Onan generator. There must be a charge controller already present somewhere right? If so, then has anyone replaced the factory CC with one specifically for the solar panel feed?

Example #2: on some fantastical week when the sun is gone and shore power would be available, what automated provision could there be to use shore to power the rig and charge the batteries without manual actions and interventions in order to not fry critical components. This is relevant in pre planning > design > interoperability.

I don't expect a lot of traffic in this thread and I'm cool with that. If on the offhand chance someone who may or may not be named BOB spent the time and money and has something to offer around this ask, then goody for me and thanks in advance!


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[Bullitt6283]

Hey Captain, Your Example #1 needs to be split into 2 parts:

Example #1A- When the vehicle engine is running, a solenoid switch ties the chassis battery and the house battery together, so that both batteries are charged by the alternater. It's a dumb brute-force system, but it works.

Example #1B- When the generator is running, 120 volts is applied to the house wiring, just as it is when you connect to shore power. The very same 120 volt>12 volt converter which charges the house battery when plugged into shore power charges the house battery when the generator is running.

Example #2- If you are running on shore power, the house battery is being charged by the converter OR by the solar system, depending on which system happens to be providing more voltage to the house battery at any specific time. The systems do not interact with each other, they simply look at the house battery voltage and provide power, or not. Simple. If there's no sunshine, the solar system won't be working. No manual intervention is needed

Now, on the other hand...
There are high-zoot systems you can buy to integrate all this and allow you to automate what's going on.... automatic generator starters...automatic load shedding...shore power augmentation from a solar system....etc...etc.
But why go to all the trouble.

BTW my name isn't Bob.

[Captain Morgan]

*Phil Hartman* YOU ARE CORRECT SIR!

Today I went by and pulled up the bed and examined the skimpy system. There's not really any extra room in the space for larger replacements and it isn't ventilated anyways.

So far my pre planning is pondering where to mount a new 3,000w + inverter and where to stow 4 banks of batteries. Then there's the matter of tieng it all back together.

On this 29MV there are two identical size bays one on either side that should be large enough for the batteries. I would have a support cage welded to the frame for the weight. I know I could use the bay closest to the house system as shown, but I want to load balance the weight mid way in the rig.




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[Captain Morgan]

I was looking at this factory rats nest again and I think I can clean it up and get a new 3k inverter in there, maybe consolidate some of the parts and functions. I could reuse the Transfer Switch unless I find that feature built in to a new sine wave inverter.

I want the new inverter to be a whole house supply and not a couple of extra outlets somewhere.

I'll also need to add a solar charge controller and run the cable to the new battery banks. I might be able to re route and re use the heavy cables going to the existing house battery.

I semi have all the connectivity laid out. I looked at every RV solar diagram posted anywhere and some are pretty good, but each one is off a little on something.


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[Bullitt6283]

Have you determined a way to route the solar cables to the roof?






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[Captain Morgan]

Not the sure fire way, only the sewer pipe speculative way.


I can bind all the solar cables to one buss bar and run a single cable through an existing hole in the roof but that's still a pita once I get inside and try to get down again.




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[Captain Morgan]

OK I want to bump this thread since it has the pics already.

I'm not sure I'm going to get all the projects done and the solar panels installed in the time-frame I wanted.

So if I do this piece-mill and install the batteries and a larger inverter, what else do you think I need until the panels and charge controller?

If for some time or for all winter I charge the LI batteries from the generator and or alternator, and I just swap out the existing inverter with a larger one, what am I missing?




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[Bullitt6283]

Do you have a converter with the charge profile suitable for charging LI batteries?



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[Captain Morgan]

I haven't purchased ANY equipment yet which is why I'm in a crunch. The default stuff in that came with the Grayhawk are in the pics.

I'm 99% sure which batteries I'm buying but the charge controller, inverter upgrade and any DC-DC etc are still up in the air.


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[Daring to Dream]

I have a Jayco 2019 Greyhawk 30z and want to go full 30 + amps which 3500 to 4000 watt to oversize a bit but this size inverter is hard to find.
After looking at wiring and not wanting to mess with that mess I started planning a stand alone that i can mount in 1 or 2 compartments and just plug shore power into. Seems like besides not getting in to rv wiring and trying to figure out some of the wiring size and other issues that I can also use it for remote cabin power. WIND and SUN have prebuilt systems that are very nice and very expensive. I am look at assembling myself a Growatt 3000 48v to 120v with built in mppt solar charge controller and adding growatt lithium batteries. This is a not so expensive system.
I havent gave up on the though of going the direction you are going. Will be watching to see how well it goes for you Capt

[AllanBaird]

Just FYI to everyone,
I ran my solar wires down through refrigerator vent on the roof down to the under chassis of the motorhome. slick as can be

[colby]

Not sure if this helps or not; however, Explorist Life did a video on an end-to-end Class C DIY solar install - https://youtu.be/9fmL1RfmZJk?si=1go9UbBe74W5dvtS. Might be a worthwhile watch as it should answer #2 with their setup.