How is this for a power system? Solar vs battery balance?

[Zirdu]

One issue I see with your proposed set up is that the Victron 100/30 charge controller has a limit of 440 watts of solar, for a 12Volt system. See the specs on the 100/30. So even your 540 watt total of solar panels would exceed the limits of the Victron 100/30. If you want that much solar, you might need a bigger controller, perhaps the Victron 100/50 might do the trick?

 

[craig333]

Nothing wrong with a little overkill but you may not need as much as you think. I've found three hours of sun a day cover my needs and I'm not being conservative with my usage.

 

[LosAngeles]

thanks.

Being in the Midwest now.... lots of grey skies , rain, and non-CA skies, especially in winter, and the big 12v fridge is a bit of a power pig. 4.4 amp hours when running, i seem to recall. Yikes.

so leaning towards overkill, indeed.

Nothing wrong with a little overkill but you may not need as much as you think. I've found three hours of sun a day cover my needs and I'm not being conservative with my usage.

 

[Stokeme]

Overkill, with panels, can be an issue if you do not “overkill” everywhere. Your entire system needs to be balanced. I would recommend you do not use Hallmark, as your #1, for solar guidance. #1 should probably be Battleborn, how do you keep your $$$ Batteries safe from harm? #2 should be Grape Solar as to their recommendation for a balanced system. Call & talk to several folks in the Solar or LiFePo4 business.
#3, have you considered how much weight, in panels, will be on your Camper roof? I looked & did not consider you were talking glass panels. They weigh 25.65 lbs/panel. 3 panels is 77 lbs. 4 panels is 102.6 lbs, ouch. How are you lifting up your Camper roof? That is some weight. If you really need that much W, consider Flex panels, higher W Flex do exist if you research. One more thought, electrical guru could answer, or Solar expert, how many panels can you wire in parallel, issue free, safely? 4 seems like a lot of possible added wiring. Not sure if they make a 4 in 1 plug. There is a 3 in 1. I’d suggest 3 panels with a larger Victron. 540W really is a ton.
Sorry last $.02, my FWC has a rear exterior wall solar plug. I carry a 100W flex portable, never used yet, to add W to my roof, when needed. Flex 120W x 2 on roof. (My Shell, buildout usage, is lower 12V only) You will still need a capable controller to handle your greatest, max W output. If everything is run in parallel, it is a simple plug & play. With enough cable you can better position a portable in the Sun too.

 

[LosAngeles]

Thanks for the thoughts. Great to read.

Just to educate myself, I spoke with a Victron person, and they are very helpful

I think we will likely go with an all Victron system. 100% Victron, for a bunch of reasons.

I will say that Hallmark have been very kind, patient, and helpful, and really do want to work with us to build the camper that we dream of.

from what I know, the Hallmark roofs are incredibly strong. We will be fine with 4 Grape solar panels. Hallmark said so. I will double check with them, of course.

They make a very strong, and sophisticated laminated fiberglass product.

and... in the midwest here, when cloudy / grey / rainy..... fall winter spring.... 540 watts wont be a ton, especially with the heater and fridge running all the time. We almost always boondock, so will need lots of solar. I would rather have more solar, and almost never use the backup generator. I hate generators.

just my 2c.

Overkill, with panels, can be an issue if you do not “overkill” everywhere. Your entire system needs to be balanced. I would recommend you do not use Hallmark, as your #1, for solar guidance. #1 should probably be Battleborn, how do you keep your $$$ Batteries safe from harm? #2 should be Grape Solar as to their recommendation for a balanced system. Call & talk to several folks in the Solar or LiFePo4 business.
#3, have you considered how much weight, in panels, will be on your Camper roof? I looked & did not consider you were talking glass panels. They weigh 25.65 lbs/panel. 3 panels is 77 lbs. 4 panels is 102.6 lbs, ouch. How are you lifting up your Camper roof? That is some weight. If you really need that much W, consider Flex panels, higher W Flex do exist if you research. One more thought, electrical guru could answer, or Solar expert, how many panels can you wire in parallel, issue free, safely? 4 seems like a lot of possible added wiring. Not sure if they make a 4 in 1 plug. There is a 3 in 1. I’d suggest 3 panels with a larger Victron. 540W really is a ton.
Sorry last $.02, my FWC has a rear exterior wall solar plug. I carry a 100W flex portable, never used yet, to add W to my roof, when needed. Flex 120W x 2 on roof. (My Shell, buildout usage, is lower 12V only) You will still need a capable controller to handle your greatest, max W output. If everything is run in parallel, it is a simple plug & play. With enough cable you can better position a portable in the Sun too.

 

[Stokeme]

Great that you put in the research. Happened to be looking for tire info just now. The weight issue, I brought up, was not whether your roof could handle the 77-106 lbs. I think FWC can handle 150-200 lbs? Hallmark more? It was about popping open, & up, the top of your roof. How will you be lifting your roof? Have you tried to lift a roof carrying that much weight? Have they discussed that with you? It might be difficult, inquire.

Thumbs up to video below!

 

[LosAngeles]

I will be getting the "super manual" roof lift.

Hallmark says to use a 20v Dewalt brushless Lithium drill, and it works great. Drill costs about $120 or so.

Here is an example with a guy with a less powerful drill.

cool, eh?

The built in power lift roof costs an extra $3,800 and I dont want the added cost and complexity.

Great that you put in the research. Happened to be looking for tire info just now. The weight issue, I brought up, was not whether your roof could handle the 77-106 lbs. I think FWC can handle 150-200 lbs? Hallmark more? It was about popping open, & up, the top of your roof. How will you be lifting your roof? Have you tried to lift a roof carrying that much weight? Have they discussed that with you? It might be difficult, inquire.

 

[ckent323]

Many boats have solar arrays capable of generating over 500 W. A recommendation in marine installations that I think is worth consideration for a large RV/Camper solar install is to use multiple solar charge controllers. Then feed the outputs to a single input to the battery.

Here is a reference:

You can skip to about 19 minutes in to hear about using multiple charge controllers.

Dividing up the work over multiple controllers ensures you don't lose all power if a controller fails.
It also gives benefits relative to mitigation of shading effects (or degradation/loss of a panel) same as on a boat.