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Sanity/Safety Check Before I Assemble My Configuration

rcnjstudent

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Joined
May 8, 2022
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I think I have just about everything that I need to begin assembling my mini portable offgrid system. This will be a 12V system wired in parallel on the panels. This is more meant for grid down scenarios after storms and stuff to keep my fridge powered and a couple of other key essentials, mainly my router/WiFi/VoIP phone/charge a laptop. Below is the breakdown of everything that I have with links. Does anyone see anything else that I'm missing that could be a critical safety issue?

-MISSING - extension wire between panel and 4 to 1 branch connector. Would as low as 10AWG suffice? Was thinking about buying 4x of these for positive/negative wires https://www.amazon.com/dp/B00A40QRXK
-MISSING - 4 to 1 branch connectors - anyone have good recommendations? Was looking into these Renogy ones but wasn't sure if they were over priced, saw cheaper ones on Amazon but they were no-name brands which had me a bit concerned https://renogy.com/4-to-1-solar-branch-connectors-mmmmf-ffffm-pair/
-MISSING - Solar Panel Connector Fuses - Do I need to put fuses on the end of each of my solar panel connectors between panels and branch connectors? Some people seemed to suggest when doing 4x 100W panels in parallel this could be a fire/safety hazard without it in case of malfunction at branch connector. Would 10A suffice with 100W panels? I think they're only about 5A in output.

Renogy 200 Watt 12 Volt Monocrystalline Solar Panel Starter Kit with 2x 100W panels (comes with panels, 30A PWM controller, 1 Pair - 20ft 10AWG Solar Panel Connectors Adaptor Kit*, 1 Pair - 8ft 10AWG Tray Cables*)

Renogy 200 Watt 12 Volt Monocrystalline Solar Panels - 2x 100W panels

12V 200Ah Lithium Iron Phosphate Battery w/ Bluetooth

2000W 12V Pure Sine Wave Inverter

1/0 AWG Battery Cables for Between Battery and Inverter

Littelfuse MEG250XP MEGA Slo-Blo Automotive Bolt-Down Fuse for Battery Wire
 
Eeewww, get rid of that controller and get a MPPT controller from EPEver or HQST or Rich Solar or even PowMr and you'll get a LOT better performance out of the panels. You'll also be able to run them in a 2s2p configuration and avoid having to have all the extra fuses. Just get 4 panels and the MPPT for about the same price as the 4 panels and kit. They mark up the kits a lot for "convenience".

With a 12v battery and 400w of panel you're going to want at least a 40a SCC or you'll just be nerfing yourself. Remember, the wattage limits are *SCC AMPS x Battery Volts* so a 30a controller on a 12v battery is going to max out at 360w in a perfect world, but PWM is less efficient than that so your net effect is probably going to be 5.4a * 4 panels * 14v = 302w maximum which is wasting $100 for panel you can't use.

Pro Tip: If it has USB ports on the front/side it's NOT a MPPT controller, it's a PWM telling you lies on the sticker. Also, if it's less than about $100 it's a dirty, dirty liar.
 
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What the heck- I have one coming :)

I loved the windy nation P30L but it wasn’t provided with usb outputs. The Giandel inverter did, though.
I can measure the no-load draw on the 12V usb charger I use now, and the 120V plugins, but the Giandel wasn’t measurable.
I have high hopes for the triron
 
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