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Solar panel investgation

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Chordaroy

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Apr 7, 2020
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Hi I’ve been given these panels. See attached pic.
If you would be so kind I would like advice on building a system with some or all of them.
I live in Australia -31.06, 152.84.
I have 8 of them second hand. Yet to test them.
I want to power a fridge. I’ve got a freeer I’ve changes the thermostat to use as a fridge. It rated at 365 kWh per year as a freezer. Should get half that as a fridge. Also run electronic equipment - computer, recording kit. Occasional guitar amp, power tool.
What is the max controller I can use? Will the EPEVER MPPT 40A do the job?
My main concern is over powering the controller and whether to connect series or parallel or both.
Are these components in the right area

Inverter https://www.ebay.com.au/itm/Large-S...270161?hash=item3abfc21291:g:82AAAOSwS3JedJac

Controller https://www.ebay.com.au/itm/EPEVER-MPPT-Solar-Charge-Controller-12V-24VDC-Battery-Regulator-40A-30A-20A-10A/372087423549?_trkparms=aid%3D1110007%26algo%3DHOMESPLICE.DISC%26ao%3D1%26asc%3D20200220090753%26meid%3D0e360abd9b13435dbc70a6be8afb4e86%26pid%3D100009%26rk%3D1%26rkt%3D1%26mehot%3Dpp%26sd%3D223639325207%26itm%3D372087423549%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3Ddefault&_trksid=p2047675.c100009.m1982

Battery https://atomicnumber3.com/collections/frontpage/products/120a-battery-12-volt-deep-cycle-lithium-ion

Thanks
Chord
 

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Cool!
Which controller did you get? 1500w of solar you will need a LOT of controller at 12V, is over 120A... at 24 is over 60A, at 48v over 30A... so, you have decisions to make.
 
Hi. I haven’t bought anything yet. Trying to work out exactly that. I don’t have to use all the panels and because there second hand I’m thinking they won’t be putting out as much as they once did.
Do you know how many of these panels I would use for 40amp controller as selected above?
 
Chordaroy said:
Hi. I haven’t bought anything yet. Trying to work out exactly that. I don’t have to use all the panels and because there second hand I’m thinking they won’t be putting out as much as they once did.
Do you know how many of these panels I would use for 40amp controller as selected above?
Click to expand...
I’d need to know what battery voltage you are using.
 
Chordaroy said:
I was

I was thinking of using two 12v 140 amp hr lithium batteries in series.
Click to expand...
40A at 24V is 960W, so, 5 panels could fill it, say the panels are about 10%weak, and you average 80% sun... um... 136Wper panel... 7 would be about full, so all 8 would be over full most of the time.
 
Supervstech said:
40A at 24V is 960W, so, 5 panels could fill it, say the panels are about 10%weak, and you average 80% sun... um... 136Wper panel... 7 would be about full, so all 8 would be over full most of the time.
Click to expand...

Thanks that’s tremendously helpful. Much appreciated. I’d be confident in 4 hours full sun across the arc sky available. Some trees and a hill are shade creaters.

Rooky question. Is that 960 w of solar panels in series or parallel?
 
Last edited:
Chordaroy said:
Thanks that’s tremendously helpful. Much appreciated. I’d be confident in 4 hours full sun across the arc sky available. Some trees and a hill are shade creaters.

Rooky question. Is that 960 w of solar panels in series or parallel?
Click to expand...
Doesn’t matter. Watts are watts. Since you have the mppt, I’d go series, but be safe! All that in series is a LOT of volts. Make sure you do not exceed the controllers max voltage... or you will destroy it.
 
You want to pay careful attention to these panel's Voc, which = 46.2V. You need to know the maximal voltage that your controller will handle. That EPEVER MPPT 40A has a max voltage of 150VDC. Wire two of those panels in series and you'll get 77.2VDC when current is flowing, but 92.4V when the circuit is opened. Wire three in series and the numbers are 115.8V and 138.6V respectively. BUT, right at freezing, their Voc will =150V. A few degrees below freezing, and the controller could get fried. The first rays of light on a frosty July morning might be enough to destroy that controller if three are wired in series. If your system is going to be 24V, then wiring them in a 1S5P sequence would work. After you get them wired though, and you have real-time amperage readings, if the output is consistantly less than 35amps, you might wire in a sixth panel and call it done.
 
MichaelK said:
You want to pay careful attention to these panel's Voc, which = 46.2V. You need to know the maximal voltage that your controller will handle. That EPEVER MPPT 40A has a max voltage of 150VDC. Wire two of those panels in series and you'll get 77.2VDC when current is flowing, but 92.4V when the circuit is opened. Wire three in series and the numbers are 115.8V and 138.6V respectively. BUT, right at freezing, their Voc will =150V. A few degrees below freezing, and the controller could get fried. The first rays of light on a frosty July morning might be enough to destroy that controller if three are wired in series. If your system is going to be 24V, then wiring them in a 1S5P sequence would work. After you get them wired though, and you have real-time amperage readings, if the output is consistantly less than 35amps, you might wire in a sixth panel and call it done.
Click to expand...
Thanks very much for that information, much appreciated. Been out of range, sorry for late reply.
I’ve actually purchased the Victron Blue Solar MPPT 100/50 (link below). Recommended by electrician nephew. Looking at the specs it says it’s max PV open circuit voltage is 100v ☹️but states that if more PV power is connected, the controller will limit input power.
Does this protect from frying the controller? Could you please offer your thoughts?
Also what does 1S5P mean? Another rookie question.
Thanks for all the help.

 
By the way did some research on the batteries above this is what I found out from a review of the batteries by another person. There comments below.
- Sirius Force/Think Out buy the batteries in bulk from AliBaba.com suppliers in China.
- They ask the Chinese supplier to put LiFePo4 35AH in a 100AH battery case and pay about $100 per battery.
- They brand the batteries either Atomic3, Maverick or Optimum Ion.
- Then they false advertise the 35AH as 120AH or 100AH and sell them for $600 in Australia.
- The Australian companies selling REAL 100AH batteries for $1,000+ lose customers to a competitor that can get away with scamming their customers because the average person will never test to find the true AH.
- eBay or Catch are the only one who can take action against this seller but instead they help the scam seller by deleting bad reviews and the rare customer who realises it's a scam accepts their refund and stays silent.

I have to buy 10 of these for the company I work for so our product can work for as long as possible in a remote area. We have to be 100% sure they will work.

I found all of this out after spending 2 days on the internet reading everything I could, forums, reviews, contacting suppliers on Ali Baba. I asked a few trustworthy Australian battery sellers why they are selling the same 12V 100AH LiFePo4 for double or triple the price of Atomic3, Maverick or Optimum Ion. They all said the same, that they are false advertising, selling fake batteries, lying about AH, pretending 30AH is 100AH or even 300AH.

But no one seems to be doing anything to stop them?
 
Chordaroy said:
Thanks very much for that information, much appreciated. Been out of range, sorry for late reply.
I’ve actually purchased the Victron Blue Solar MPPT 100/50 (link below). Recommended by electrician nephew. Looking at the specs it says it’s max PV open circuit voltage is 100v ☹️but states that if more PV power is connected, the controller will limit input power.
Does this protect from frying the controller? Could you please offer your thoughts?
Also what does 1S5P mean? Another rookie question.
Thanks for all the help.

Click to expand...
1S 5P means all in parallel, keeping the VOC low as possible.

Keep in mind the amps will be 5 times what listed max is.
Since you have a 100V ceiling, 2S 4P would be the lowest you can amp all the panels.
 
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