Looking for charge controller advice. New builder.

Sam98961

New Member
Joined
Sep 3, 2021
Messages
7
Hello! I did look through previous posts first before asking and didn't see anything related to what I have. To begin let me reiterate, I'm very new and very excited to put together a learning kit so my dad and myself can eventually work up to much larger projects. I recently came across 6 solar panels for a very good deal. They are SS270P-72 panels. Rated output is 270 watts, 44.4 volts and 7.6 amps. I tested each one about an hour ago in direct sunlight and got 41 volts and 5 amps from each one.

What I'm looking for is advice to keep cost down since this is my first project. I honestly have no idea what my end goal is other than learning so please be patient with me. :) I'm looking for info on how I should wire them, how many in the series and how many in parallel. I'm thinking 3s2p and getting a 150v/20a SCC or go 2s3p and getting a 100v/20a SCC. I want to still use 10 gauge wire and I think I can with either configuration. Is one preferred over the other for charging batteries? Do I want/need to go with 12v or 24v?

I certainly want to use lithium iron phosphate batteries over lead acid eventually. I have one of those batteries in my RV and after studying them they are certainly superior. I'll buy those later as they are super expensive and I kinda want to build my own from cells after watching a ton of videos and reading up on it.

I greatly appreciate any advice yall can give and if you need more details please let me know and thanks in advance!!

Pics attached are the label from the panels and them loaded up ready for the trip this weekend!
 

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Sam98961

New Member
Joined
Sep 3, 2021
Messages
7
Well, just a quick update, I got them all set up on the frame my dad and I built. I bought this charge controller.
https://www.amazon.com/dp/B07G35KPX...olid=1XWFXQ2TKEUAO&psc=1&ref_=lv_ov_lig_dp_it
I think I'm going to go with 2s3p to get 88v and 21a. Now all I need are some batteries and an inverter!! I'm really excited to get this all set up. Attached are a few pics to show how we have them installed. Gets about 7 hours of sunlight each day. Constructive criticism is greatly appreciated.
 

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MisterSandals

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Nov 5, 2019
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Location
Silicon Valley
What is the Voc of your panels, the max input voltage of your SCC and the coldest temp you want your system to handle (before your SCC gets overvoltaged)?
 

Sam98961

New Member
Joined
Sep 3, 2021
Messages
7
The Voc is 44.1V each. I went a little over on the SCC since this is just the learning project and I want to reuse some of this when I move to a more permanent solution. I'm looking at lithium iron phosphate batteries right now and the benefit of 24v over 12v. Inverters over 12v are expensive. hahahaha
 

Sam98961

New Member
Joined
Sep 3, 2021
Messages
7
Hey yall. Sorry to keep blasting my own post but I wanted to provide an update. My first solar project is complete. I still have to pretty up the wires but over all I'm really happy with the outcome. Next project is to build a much larger solution. This was so much fun. Attached are some photos of the end product.
 

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12VoltInstalls

Solar Addict
Joined
Jan 18, 2021
Messages
1,351
Location
Vermont
I guess I want to know if it’s any good :)
Longevity in other words.
Maybe you’ll tell us…

Judging by your volts (in the range so to speak) I’m guessing you went with lead acid for batteries?
 

mactech

Solar Enthusiast
Joined
Sep 15, 2021
Messages
33
Nice project you have there Sam. I am doing much the same thing to power my observatory. What is your panel tilt and did you go with 24v?
 

Sam98961

New Member
Joined
Sep 3, 2021
Messages
7
I guess I want to know if it’s any good :)
Longevity in other words.
Maybe you’ll tell us…

Judging by your volts (in the range so to speak) I’m guessing you went with lead acid for batteries?
Of course! It has great reviews. I'm using a single lithium ion phosphate 12v battery. I'm not powering very many devices. The peak voltage is around 120volts and 11 amps.
 

Sam98961

New Member
Joined
Sep 3, 2021
Messages
7
Nice project you have there Sam. I am doing much the same thing to power my observatory. What is your panel tilt and did you go with 24v?
Thanks! I didn't get an exact measurement of the tilt but the panels are 44 volts each. I have 3s2p going. Each panel puts out about 35 volts at the most. That area gets plenty of sunlight during the day. Also, I'm using just 1 12v 100AH Lithium Iron Phosphate battery.
 
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