Class A 50A System design for review

overclocked92

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Feb 18, 2021
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Complete newbie looking for input. Basing design off "RV with Tito" recent install but using 8 Nature Power 215 watt panels purchased from Home Depot when they were on sale. I was going to wait for 24V version of Multiplus II 2-120 but it keeps getting delayed and I want to get on with install.

Would appreciate everyone's thoughts on panel wiring and charge controllers. I've considered wiring the 8 panels 2s4p and using one charge controller (150/100) or 2 x 2S2P with 2 charge controllers (150/60). Leaning towards the configuration drawn using 4 charge controllers for redundancy and resiliency.

Installing on a 34' Beaver Monterey with a fiberglass roof so planning to use VHB / channel strut mounting with z-brackets to attach panels to channel strut. Went with the physically smaller panels to maximize wattage I can fit on roof around existing equipment. Aware I need to be careful about shading which is another reason I'm leaning towards 4 charge controllers.

Look forward to everyone's input and discussion.
MableSolar_V1.jpg
 
Joined
Nov 30, 2019
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Each battery should be parraleled to a busbar with its own class t fuse
With the current config the outer batteries get more wear and tear and the middle one gets less.
I suspect those busbars are made of brass.
Please don't use brass busbars.

4 solar charge controllers is overkill in my opinion

I suggest you make your panel configuration 4s2p and get a solar charge controller that can handle that configuration.
4s2p doesn't require any fusing so you could get by with A double pole single throw breaker that is only used as a means of disconnect

No disconnect is needed on the system side of the solar charge controller, the breaker on the pv side will isolate the charge source.
 
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Nov 30, 2019
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You could make really sweet system around the lynx dc distribution kit.
lynx_power_in<->lynx_shunt<->lynx_distributor

You would need pepper spray to keep the nerds from swarming.
 

caymaanedge

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Jul 19, 2020
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I would drop two of the solar controller and the raspberry pi. Use a lynx distributor and Cerro/touch. Rpi are hard to get and 3x the old price anyway.
 

overclocked92

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Feb 18, 2021
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I would drop two of the solar controller and the raspberry pi. Use a lynx distributor and Cerro/touch. Rpi are hard to get and 3x the old price anyway.
Already have a spare pi so I'll probably stick with that but yes it is crazy what they are going for now if you can find one.
 

Zil

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May 27, 2020
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I second Joey. Each 4s battery needs a BMS. Each needs a Class-T fuse. A quality BusBar is how to do that.
Please fuse the main circuit from the battery at the battery end of the circuit.
Rule Number One. Fuses protect wires. That 400A fuse should protect a 4/0 cable or larger. Do you need a 4/0 cable? Or will a 2/0 be satisfactory? Work through the system's circuit and determine the awg needed by using a voltage drop table. Then select the fuse ampere.
Battery #1 --> Fuse --> BusBar #1
Battery #2 --> Fuse --> BusBar #1
Battery #3 --> Fuse --> BusBar #1
Battery #4 --> Fuse --> BusBar #1
-> BusBar #1, each branch circuit --> appropriate sized fuse --> device.
 
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