FYI Solar 101 - A General Guide to Solar in your RV or Motorhome

[Notsotalltexan]

Is that the one coming tomorrow?

I've received several emails from FedEx about items drop shipped from various suppliers all ordered by A.M.Solar. Very likely the charge controller will be included in one of the boxes arriving tomorrow. I just watched a video by Garret at A.M.Solar regarding sizing the correct charge controller. The equation says solar array watts X .9 / 12V = amp output current. Since I will have a 1200Watt array x .9 / 12V I get 90 amp output current. The charge controller Jack at A.MSolar recommended is the 150 | 85. Garret said this difference won't hurt the controller, I just won't be getting the benefit of the additional amp current. At least that's how I understood it. The YouTube link.

 

[Richpatty]

And that is correct… which is why I have a 150/100 as I have 1440 watts. Also, the odds of getting all 1200 watts is pretty low. I think the best I have EVER seen is 1376 watts. But if you want to add more panels later, it could be a limiting factor…. But if you don’t, it will not be.

 

[Notsotalltexan]

Thanks Rich I am assuming I can call Richpatty Rich.

 

[Richpatty]

Thanks Rich I am assuming I can call Richpatty Rich.

Ha. Yup. Patty is my wife.

 

[Kevin D Pem]

It

I have not received it yet. Jack at A.M.Solar sized my system based upon what model coach I have and what I told him I was probably going to need especially that I was not going to be using my A/C when relying on solar power. It is a Victron 150 | 85. There will be six 200W 24V panels charging two LifeBlue 200Ah batteries. I'm trusting in his expertise. I think I'd feel better if I had requested a 150 | 100 but I'm deferring to his experience. I guess I could always add a smaller controller later.

You well known in the industry (electronics), that it's best to oversize your electronic components. Just remember that salesmen are salesmen. The engineers that designed the unit stated what were safe limits for reliability.

The controller is not a limiting device, this statement is very important to remember. If the stated wattage in panels is exceeded it will be failure time. (Yes components were oversized), but not for the capacity, but reliability.

It is known that the panels were rated in the lab environment, and will likely never produce the rated output. . There is one Time that they have been known to peak. The cloud effect.

Because I rely on solar, I use smaller repetitive systems, (One down three to go type system). That sets my system with 4 60amp controllers. The manuals I have rate a 60amp controller to handle at 12v system 720 watts of panels. 24v system 1440 watts of panels. This would be battery system voltage, and nothing to do with panel voltage.

For a little more information, mppt controllers are smart boost converters. These converters are most efficient at no more than 2.5 volt difference between high and low sides.

I wish you luck on your installation.

 

[Notsotalltexan]

That "pink wire" was disconnected from mine for a while until I asked @Chuggs about it and saw his was connected. Yeah, it's too short for sure!

Hey Neal--

Thank you for the goodies. I using the green coffee cup right now.

I've almost received all of what I ordered from A.M.Solar. Since my Ventana is most likely very similar to your coach, you probably have the basement pullout battery shelf. Relative to this battery compartment, which basement compartment did you mount your board with MPPT and other components? Is it right next to the battery drawer on the same side or across the basement on the opposite side?

 

[Neal]

Glad you got it and you're welcome.

I mounted mine between the chassis rails in the slideout bay. Bad idea as I later got HWH Active Air and that's where that controller should have gone but my stuff was in the way. If I did it over again I'd put it closer to the basement door driver's side just opposite the batteries on the wall. If going LifePO4 then in the battery compartment itself.

 

[Notsotalltexan]

It

You well known in the industry (electronics), that it's best to oversize your electronic components. Just remember that salesmen are salesmen. The engineers that designed the unit stated what were safe limits for reliability.

The controller is not a limiting device, this statement is very important to remember. If the stated wattage in panels is exceeded it will be failure time. (Yes components were oversized), but not for the capacity, but reliability.

It is known that the panels were rated in the lab environment, and will likely never produce the rated output. . There is one Time that they have been known to peak. The cloud effect.

Because I rely on solar, I use smaller repetitive systems, (One down three to go type system). That sets my system with 4 60amp controllers. The manuals I have rate a 60amp controller to handle at 12v system 720 watts of panels. 24v system 1440 watts of panels. This would be battery system voltage, and nothing to do with panel voltage.

For a little more information, mppt controllers are smart boost converters. These converters are most efficient at no more than 2.5 volt difference between high and low sides.

I wish you luck on your installation.

Thank you Kevin.

Glad you got it and you're welcome.

I mounted mine between the chassis rails in the slideout bay. Bad idea as I later got HWH Active Air and that's where that controller should have gone but my stuff was in the way. If I did it over again I'd put it closer to the basement door driver's side just opposite the batteries on the wall. If going LifePO4 then in the battery compartment itself.

Thank you. I will opt for the battery compartment due to ample room. BTW, my eight batteries were all replaced by original owner in 2020. He accidently frozen his 2017 factory flooded batteries. He replaced them with Duracell, 6V. I guess they're in series so 12V system. I'll try to sell them locally since they've still got lots of life left. I might post them here. Maybe someone in Texas might be interested. They'd be great for a golf cart too.

 

[Richpatty]

I did the same as Neal (between chassis rails), but then moved it for ease of access to the battery compartment when I re-did my battery compartment for lithiums.
No sure if putting the controller in the battery area when it is open to the environment would be good for it?

 

[Notsotalltexan]

I did the same as Neal (between chassis rails), but then moved it for ease of access to the battery compartment when I re-did my battery compartment for lithiums.
No sure if putting the controller in the battery area when it is open to the environment would be good for it?

Good Morning Rich--

That's a little concerning to me too. My rig is in a 14 wide x 50 foot storage so I have to pull her out just too open my basement doors all the way. It gets washed and waxed on Thursday so that's when I can make my determination.