Solar array not performing to rated power (not even half)

[Hedges]

I would only recommend this with lead-acid, e.g. automobile starter battery. That can take brief excess current.
Lithium could be damaged, so don't use that.

No, I meant battery connected directly to lead-acid battery, no charge controller.

Individually to charge controller for 24V battery, PV voltage would be too low to deliver current.

You already tried 2s2p. Try 2s, then the other 2s, then swap which panels in series and try again.
The idea is to see if some panel is under-producing the others.

Are these new?
I had some degrade after 15 years use.

Can you measure Voc of each panel? Isc?

 

[chamberwil]

I would only recommend this with lead-acid, e.g. automobile starter battery. That can take brief excess current.
Lithium could be damaged, so don't use that.

No, I meant battery connected directly to lead-acid battery, no charge controller.

Oh ok, got you.

 

[Madcodger]

Comment on similar panel on Amazon:

not 180Watts, that is the lab theoretical test. in reality you can get 125 out of them. seem to be built decently, the connectors start chalking up almost instantly in any direct sunlight. my set of 4 have been outside for 4 weeks and the one set of connectors that get about 1 hour of sunlight a day are already chalky white. This means I'll need to replace them in a year. I had 2 panels have to be replaced as they ship them with barely any protection via UPS and two arrived broken. Amazon takes care of the returns (do NOT call the maker, deal with it through amazon if you want fast service). they are not tolerant at all to any shading, even a line shadow from a wire will take the panel offline. so make sure there is no chance at all for shadows in your mounting location. 4 of these in the sunshine state and the higest power output I have seen from them is 500 watts total, so that is 125 each. so design accordinly. This is tilted correctly at the sun. I expect even less power from them when they are flat on the roof of the camper.

https://www.amazon.com/Newpowa-Moncrystalline-Solar-Efficiency-Module/dp/B0772PD96K

Just FWIW, I've had 6 of this manufacturer's 210 watt panels for just under a year, and they've performed like champs.

 

[littleharbor2]

New or used panels?

Do you have an ammeter able to measure short-circuit current of the panels?
If so, measure each one individually.
Then connect each to a 12V lead-acid battery, and measure the current. See what wattage is indicated. Voltage a bit below Vmp, but should be somewhat close.

Voltage, when connected to a 12 volt battery will be only slightly higher than actual battery voltage. You might try connecting to a 12 volt fan or light to get a better idea of vmp.

 

[Shimmy]

I clean and put WD40 on each connector.

Are you saying you put WD40 on the electrical terminals themselves? Not a good idea.

 

[chamberwil]

Are you saying you put WD40 on the electrical terminals themselves? Not a good idea.

Yes I did. Why it’s it a good idea? Doesn’t it clean and prevent future rust?

 

[Shimmy]

Yes I did. Why it’s it a good idea? Doesn’t it clean and prevent future rust?

You need to remove all the residue after applying; the company makes a specific version for electrical contacts but even that gets mixed reviews.

 

[pollenface]

If you get close to rated power, you are very lucky.

As for myself (during load tests in strong midday sun with a heat gun)
300w gets 256w
750w gets 436w
380w gets 329w
1160w gets 713w

Use a pv orientation/inclination tool to help get the best angle for your location. It varies from month to month as the sun changes its position in the sky, but if you are close to optimal it definitely helps. My optimal yearly inclination is 28.2 degrees.

 

[littleharbor2]

Use a pv orientation/inclination tool to help get the best angle for your location. It varies from month to month as the sun changes its position in the sky, but if you are close to optimal it definitely helps. My optimal yearly inclination is 28.2 degrees.

Get the "Solar Tilt" app on your phone. Great app for free. Has a built in tilt gauge. and will give you all tilt info for your location and anywhere on earth for today or any day of the year.

 

[chamberwil]

Get the "Solar Tilt" app on your phone. Great app for free. Has a built in tilt gauge. and will give you all tilt info for your location and anywhere on earth for today or any day of the year.

Thanks for this. For my location it recommended 15 degrees. My panels are at 13-14 degrees, so I am on point. Is 9 in the morning so I am monitoring the PV output. It a little cloud but fingers crosse.

 

[TomC4306]

I'm not expert but why do you have the panels just about laying flat? Also looks like alot of shading on them. My 1360watt array drops alot also when there is shading. I can walk in front of it and drop the watt output. LOL

I used https://pvwatts.nrel.gov/ to get the ideal tilt for my off grid array which playing with PV Watts it was 30 Deg for max production for the year. Even though I will not have them system on 24/7 matter of fact I can put the array up and take the EcoFlow home with me.

I made my array so I can tilt it just for fun and testing. A friend of mine likes to play and use the paint can trick and try to get every watt of of it when we meet up at my property.

I posted this before but here is my setup. 4 340 Watt Used panels. EcoFlow is limited to 60V and 1000watts in two seperate inputs. So these panels are two separate arrays connected in parallel. These panels are 41VOC so I can't connect in series.

The Ecoflow will be in the cabin later this is still work in progress.

.

I know I need to start a separate thread on all my solar toys I play with.


.

Wow!
That IS the best thread hijack I think I've ever seen.
Congratulations.

 

[chamberwil]

Update.. I am getting peak sun not shading these two pictures will show what going on.

 

[Q-Dog]

I would disconnect all panels, then hook up one at a time to the charge controller and see what kind of output each panel has.

 

[400bird]

For everyone saying the angle is wrong, "too flat"
Read the first post, he's at the equator, the sun is nearly directly overhead 1/2 the year. They're fine.

Update.. I am getting peak sun not shading these two pictures will show what going on.

Are the 4 panels still wired in series? If so, you should be closer to 80 volts, not 40
Something isn't right there. Try what has been suggested, test each panel individually or in groups to see if you've got any duds.

Edit: also, what are your battery voltage settings. I don't run @24 volts, so don't know the numbers off the top of my head, but 27 volts seems pretty full. Once the battery is full the charge controller will limit output to not overcharge the battery.

 

[chamberwil]

For everyone saying the angle is wrong, "too flat"
Read the first post, he's at the equator, the sun is nearly directly overhead 1/2 the year. They're fine.


Are the 4 panels still wired in series? If so, you should be closer to 80 volts, not 40
Something isn't right there. Try what has been suggested, test each panel individually or in groups to see if you've got any duds.

Edit: also, what are your battery voltage settings. I don't run @24 volts, so don't know the numbers off the top of my head, but 27 volts seems pretty full. Once the battery is full the charge controller will limit output to not overcharge the battery.

You are right I am closer to the equator. Yes, the panels are in series. At this time i am experiencing a passing shower so when the rain pass I would try each panel individually to see what I get on each. Here is a battRey voltage guide I got when I switched to 24v.

 

[400bird]

27 volts is pretty close to 100%
What are your absorption and float voltage settings?

 

[Madcodger]

Your panels are rated at 19.06V. If wired in series and all 4 operating, you should be seeing about 76V. You're seeing about half that. My guess is that ether two panels are bad but just allowing power to pass through, OR you botched your wiring somewhere. As many have said, take the system apart, test each panel, and go from there.

 

[chamberwil]

So here is the update, the panels are operating correctly. The voltage at the panels is between 80 and 95V in the sun. And the voltage inside is 37v. So the issue is my wire. I am going to run a temp wire to see what I get. I am wondering if my mc4 connection is bad. Will update you guys in a few.

UPDATE: ran new wire and got the same results as before. Rule out the wire which is a BougeRV 70 Feet 10AWG Solar Extension Cable. The voltage is high as it should be when the when the charge controller is off. Once I switch the charge controller on the voltage drops to 37-40v. Any idea. ?

 

[littleharbor2]

Are all connectors factory installed? Correct polarity is absolutely critical in dc, pv wiring. If all connections aren't as they came from the factory you may have one panel cancelling out another.

 

[chamberwil]

Are all connectors factory installed? Correct polarity is absolutely critical in dc, pv wiring. If all connections aren't as they came from the factory you may have one panel cancelling out another.

Yes they are all factory installed. I even wired the PV connection directly to the charge controller to rule out the breaker same result. Any one running panels on a 24v system, let me know if this is normal.