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Convertible Portable Solar System

TechDesigner

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Oct 15, 2021
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I am new and want to learn from others before I make too many mistakes.
I have a small camper and wanted to build a portable system that can be stored inside and set up on arrival. I bought 5 100W panels and was going to use a couple in the camper when boondocking (a couple of times a year) and then use all five on the house when not camping. I bought a cheap PWM (under $15) and a 12V marine battery.

I can purchase a different charge controller and batteries or use the ones I have. I think it makes more sense to make the house system off-grid and just plug a limited amount of items into it. I will build a mount that sits on the ground outside the camper and on the house porch roof. I may need less power in the camper. I can move all or part of the system(s) from the house to the camper. Only one location has to function at a time. I don't mind moving everything since it happens rarely. I don't expect this will replace my grid power since there is not adequate sun in this region near lake Erie.

I've spent $500 so far. I don't want to spend much but don't want to be penny-wise and pound-foolish. It would be great if I can purchase smaller/cheaper and grow the system great but I think when you upgrade solar you can't just add on, you have to toss the old. I want to avoid the "if I knew then what I know now" outcome. I wanted to find out what solutions/sizes/brands you experienced solar DIYers suggest before I buy. Let me know if you need more info or have questions. Thanks for your help!
 
bought 5 100W panels
I think when you upgrade solar you can't just add on, you have to toss the old. I want to avoid the "if I knew then what I know now" outcome.
I wanted to find out what solutions/sizes/brands you experienced solar DIYers suggest before I buy

I bought a cheap PWM (under $15) and a 12V marine battery.

So I’m not sure what you’re asking.

Are you looking to buy an inverter to make some 120V? Or you haven’t actually purchased panels yet? Or?
 
So I’m not sure what you’re asking.

Are you looking to buy an inverter to make some 120V? Or you haven’t actually purchased panels yet? Or?
I was originally going to have a 12V battery, cheap PWM charge controller, and 2-3 panels for the camper 12V system.
For the house use all 5 panels (500W), the 12V camper battery plus buy another 1-2 batteries, a larger controller that does 500W, and an inverter.

I have one 12V marine battery. I might need to buy bigger/better batteries for 500W (AGM/lead-acid/nicad, golf cart, new/used) but I heard I can't just add more batteries of a different kind or move just some of them to the camper because they all wouldn't be on the same charging cycle or charge differently. If I can't mix and match old/new and types I could leave the camper battery there and get different for home.

As soon as I bought five polycrystalline solar panels someone told me I should have spent more on monocrystalline (already purchased, so I can't toss these).

I bought a cheap PWM from China and read that I should have gotten a MPPT. I have seen both from $10 to hundreds. I read the cheap PWM may kill a battery. I think the one I have is similar to the attached pic. I think I would need to buy a larger charge controller to use all 5 panels.

The camper is old but has a charger that charges the 12V battery when plugged into 110V shore power. The camper has a 12V system with lights and a 12V fridge.

I don't have an inverter yet but will probably want one that I can take from house to camper. I have seen them from $10 to hundreds.

At home, I might be able to run lights, TV, and maybe a computer daily but I'm not sure 500W would be enough to power a fan on the gas furnace, fridge, microwave, or heater in an emergency power outage.
 

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Polycrystalline are fine. Not a drastic problem these days

A windyNation P30L is what I started with. $30-$45. Looks similar to your pic BUT it worked great for 2-1/2+ years. An epever 40A will let you run 2S2P or 3S2P (you need another panel) and is $130ish. I’m using that know with 400W 2S2P and it does fine.

To actually achieve usable power a 1200 or 1500W inverter no less than a Giandel pure sine for quality matches 500Ah of batteries ok. I run a fridge and coffeemaker and vacuum on a 1200W pure sine. You don’t want low output inverters especially on the cheaper end- you want some headroom.
the gas furnace, fridge, microwave, or heater in an emergency power outage.
That’s more than a small system will do without more panels. Def more than a 500W inverter
 
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