Did I get scammed? Solar panel question.

[AnthonyBattaglia]

I bought 8 280 watt LG panels advertised as new. I get them home and hook them up and they each max produce 125 watts / 21.5 volts. I tested them next to a brand new 350 watt panel producing 344 watts / 37.3 volts. Both at the same angle in the same sunlight.

The seller says they need to "sit all day" to have the correct read out? I was born on a Tuesday, but not last Tuesday. BUT i just wanted to check here and see maybe if I am missing something?

 

[Sean Very North]

If you can, return them.

 

[SamDeleted]

produce 125 watts / 21.5 volts

Whats the rated voltage? VMP , I guess it'll be 30v ? If so 21.5v is a problem

Are they dirty by any chance ?

 

[SamDeleted]

Whats the rated voltage? VMP , I guess it'll be 30v ? If so 21.5v is a problem

Are they dirty by any chance ?

It's meant to be 32v VMP...

unless it's 200°f outside , they are bad panels , get your money back

 

[AnthonyBattaglia]

It's meant to be 32v VMP...

unless it's 200°f outside , they are bad panels , get your money back

Yes 32. Unfortunately, I got scammed and have to go to court to get my money back. Will it hurt my system to use them at the lower voltage input?

 

[SamDeleted]

Yes 32. Unfortunately, I got scammed and have to go to court to get my money back. Will it hurt my system to use them at the lower voltage input?

Very unfortunate .. I don't think it will hurt just keep an eye on them make sure nothing gets hot , particularly the box on the back where the bypass diodes are

Panels are made up in 3 section, with a bypass diode in-between,




What I think is happening is only 2 out of 3 circuits are working, the bad one is getting bypassed - that's why you're only getting 2/3 of the volts (but I'm no expert! )

So one bypass diode will be under a little bit of stress and could over heat , or die altogether



I'd get them wired up temporarily in the sun for a trial run , give it a few days to make sure everything's is ship shape & Bristol fashion before you go through the trouble of mounting, only to find out they don't work!

 

[AnthonyBattaglia]

Very unfortunate .. I don't think it will hurt just keep an eye on them make sure nothing gets hot , particularly the box on the back where the bypass diodes are

Panels are made up in 3 section, with a bypass diode in-between,

View attachment 150556


What I think is happening is only 2 out of 3 circuits are working, the bad one is getting bypassed - that's why you're only getting 2/3 of the volts

So one bypass diode will be under a little bit of stress and could over heat , or die altogether



I'd get them wired up temporarily in the sun for a trial run , give it a few days to make sure everything's is ship shape & Bristol fashion before you go through the trouble of mounting, only to find out they don't work!

Thank you for taking the time to answer and explain that, I really appreciate it. Makes good sense.

 

[SamDeleted]

Thank you for taking the time to answer and explain that, I really appreciate it. Makes good sense.

Sorry youve had a bad first experience with solar , not everyone in the solar world is an arsehole . Just most of us ?

 

[BenFromSignatureSolar]

How do you have them hooked into your system? Do they have the same draw as the other panels? Can't really get a true picture of what they will do without pulling some amperage.

 

[AnthonyBattaglia]

How do you have them hooked into your system? Do they have the same draw as the other panels? Can't really get a true picture of what they will do without pulling some amperage.

I don't have them in a system yet; these were my first purchase towards building a system. I tested them on a Bluetti AC300.

 

[chrisski]

So since you don’t know the panel specs, its a bit tricky.

THe AC300 solar input specs:

“Solar Input: 2,400W Max., VOC 12-150VDC, 12A”

That 150 VDC is bad things happen like smoke when that is exceeded. The panels tested at 21.5 volts and seems like you could run 4S2P, but I’d really want to monitor the voltage constantly to be sure nothing funny happens. Not sure the AC300 lets you do this with Bluetooth or if it even shows on the LED display.

When its colder voltage tends to be higher, and when the panels aren’t having a lot pulled from them, the votlage tends to be higher. Even though it will probably be well underneath the voltage limits, I’d not want to hook up more panels in series than the voltage open circuit for the rating on the sticker when adjusted for temperature of the record cold day for your local area.

After running the panels and monitoring the voltages for a while, I’d consider adding more in series.

Also note that the spec says 12 amp input max, and putting two in parallel will exceed that.

 

[AnthonyBattaglia]

So since you don’t know the panel specs, its a bit tricky.

THe AC300 solar input specs:

“Solar Input: 2,400W Max., VOC 12-150VDC, 12A”

That 150 VDC is bad things happen like smoke when that is exceeded. The panels tested at 21.5 volts and seems like you could run 4S2P, but I’d really want to monitor the voltage constantly to be sure nothing funny happens. Not sure the AC300 lets you do this with Bluetooth or if it even shows on the LED display.

When its colder voltage tends to be higher, and when the panels aren’t having a lot pulled from them, the votlage tends to be higher. Even though it will probably be well underneath the voltage limits, I’d not want to hook up more panels in series than the voltage open circuit for the rating on the sticker when adjusted for temperature of the record cold day for your local area.

After running the panels and monitoring the voltages for a while, I’d consider adding more in series.

Also note that the spec says 12 amp input max, and putting two in parallel will exceed that.

Panel Specs: Max Load 5400
Pmax 280 Watts
Power Tolerance -0/+3
Vmpp 31.90
Impp 8.78
Voc 38.80
Isc 9.33
Max Sys Voltage 1000 V (IEC) 600 V (UL)
Max Series Fuse 15 A

 

[AnthonyBattaglia]

Panel Specs: Max Load 5400
Pmax 280 Watts
Power Tolerance -0/+3
Vmpp 31.90
Impp 8.78
Voc 38.80
Isc 9.33
Max Sys Voltage 1000 V (IEC) 600 V (UL)
Max Series Fuse 15 A

So since you don’t know the panel specs, its a bit tricky.

THe AC300 solar input specs:

“Solar Input: 2,400W Max., VOC 12-150VDC, 12A”

That 150 VDC is bad things happen like smoke when that is exceeded. The panels tested at 21.5 volts and seems like you could run 4S2P, but I’d really want to monitor the voltage constantly to be sure nothing funny happens. Not sure the AC300 lets you do this with Bluetooth or if it even shows on the LED display.

When its colder voltage tends to be higher, and when the panels aren’t having a lot pulled from them, the votlage tends to be higher. Even though it will probably be well underneath the voltage limits, I’d not want to hook up more panels in series than the voltage open circuit for the rating on the sticker when adjusted for temperature of the record cold day for your local area.

After running the panels and monitoring the voltages for a while, I’d consider adding more in series.

Also note that the spec says 12 amp input max, and putting two in parallel will exceed that.

Also, the panel manufacture date says 150114 . Any idea what that date is?

 

[chrisski]

Also, the panel manufacture date says 150114 . Any idea what that date is?

Jan 15, 2014? Like reverse Julian Format. Maybe Jan 14, 2014?

 

[SamDeleted]

I don't have them in a system yet; these were my first purchase towards building a system. I tested them on a Bluetti AC300.

Is it possible the Bluetti is throttling the panels output ? Giving you a false reading

Have you got a multimeter, What voltage are the panels producing 'open circuit' - try testing the voltage without anything hooked up to the panel (put the panel in the sun and use a multimeter probe in both male and female MC4 connectors)

 

[Nobodybusiness]

Is it possible the Bluetti is throttling the panels output ? Giving you a false reading

Have you got a multimeter, What voltage are the panels producing 'open circuit' - try testing the voltage without anything hooked up to the panel (put the panel in the sun and use a multimeter probe in both male and female MC4 connectors)

Best way to test.