250W solar panel only producing 60W??

Triton14

Well-Known Member
So yesterday I plugged my new fridge in to pull charge from the aux & this time I set up the blanket on the windscreen which was a much better angle to the sun, I couldnt put do this last time as I was waiting for a anderson plug extension to arrive.

Well yes I was getting more out of the blanket set up like this but still not anything close to what it is rated.

Screenshot_20200806-113029.jpg


Screenshot_20200806-114206.jpg


Even though I had the fridge going & the solar plugged in the battery was still @13.2V so not sure if that was an ideal test??

Maybe what I should do is draw the battery down to 50% @ 12.06V & see what happens then??

Looks like I will have to wait a few days anyway now for a day with full sun.
 

Swaggie

Moderator
So yesterday I plugged my new fridge in to pull charge from the aux & this time I set up the blanket on the windscreen which was a much better angle to the sun, I couldnt put do this last time as I was waiting for a anderson plug extension to arrive.

Well yes I was getting more out of the blanket set up like this but still not anything close to what it is rated.

View attachment 68989

View attachment 68990

Even though I had the fridge going & the solar plugged in the battery was still @13.2V so not sure if that was an ideal test??

Maybe what I should do is draw the battery down to 50% @ 12.06V & see what happens then??

Looks like I will have to wait a few days anyway now for a day with full sun.

Around 22 degrees is optimal....
My Companions pumped out 6 amps using there crappy controllers and there only 120 watts ...

You heard the ol saying “You can’t turn shit into strawberry jam”. :D ;)

Goodluck .
 

Triton14

Well-Known Member
Around 22 degrees is optimal....
My Companions pumped out 6 amps using there crappy controllers and there only 120 watts ...

You heard the ol saying “You can’t turn shit into strawberry jam”. :D ;)

Goodluck .
I did notice the blanket start to get on the hot side & then dropped down to 55W even with the same amount of sun.

On a side note I was trying to work out the draw from the fridge with this new meter but for some reason it didnt want to put up the Ah data so not sure whats going on there, had the source side plugged into the batter box & the other into the fridge which sounds right.

20200806_112840.jpg


Fridge runs really well though, came down to temp in just 10 minutes, empty of course.
20200806_114005.jpg


Had the fridge set on 4*c but I guess because its empty it dropped down a bit more.
 

Swaggie

Moderator
I did notice the blanket start to get on the hot side & then dropped down to 55W even with the same amount of sun.

On a side note I was trying to work out the draw from the fridge with this new meter but for some reason it didnt want to put up the Ah data so not sure whats going on there, had the source side plugged into the batter box & the other into the fridge which sounds right.

View attachment 68991

Fridge runs really well though, came down to temp in just 10 minutes, empty of course.
View attachment 68992

Had the fridge set on 4*c but I guess because its empty it dropped down a bit more.

Yeah kool mate,i have one of those meters also, look at amp/hrs.
I have mine set to around 2 degrees, put bottled water in it, the fridge will run Overtime trying to keep air cold using more amps
 

CTL

Well-Known Member
Anything over 12.7 volts with an AGM is simply surface charge. You need to get the battery down to below 80% to test the panels.


0C1CE359-1612-4640-B871-14858D121C00.jpeg
 

Triton14

Well-Known Member
Anything over 12.7 volts with an AGM is simply surface charge. You need to get the battery down to below 80% to test the panels.


View attachment 68994
Yes I sort of figured thats the next step, as I mentioned I want to take the battery down quite low, to 50%(12.06V) & see how it goes then because thats the benchmark really. where I need the most absortion.
Cheers.

You heard the ol saying “You can’t turn shit into strawberry jam”. :D ;)

I thought the saying was you can't polish a turd :confused:

I guess that saying got thrown when the mythbusters showed that you actually can polish a turd :p:p

 

Bru9

Active Member
You need to get the battery down to below 80% to test the panels.


View attachment 68994
Nope. He can just apply a large load on the battery to test panel wattage, even if the batt is full. As long as the load exceeds the panels sticker value.


My advise is to expect about only 50-60% of the sticker value which takes into account the poor winter sun & the poor angle that most panel leg systems use. And that is also about inline with the makers realistic non STD output which is usally just 60-70% at the most.
 

CTL

Well-Known Member
Nope. He can just apply a large load on the battery to test panel wattage, even if the batt is full. As long as the load exceeds the panels sticker value.

My answer was correct. Yes, there is the option you suggested but it doesn’t make my answer wrong.
 

REViXiSSE

New Member
Hi all, so I just got my new solar blanket yesterday & trialled it this morning by plugging it into my new Victron/dual battery system & according to the app its only producing 60W in what I would think is ideal full sunlight in top of my canopy.

The blanket is a Maxray & these are the specs-

SPECIFICATIONS
Max Power:250W
Max Power Voltage:18V
Max Power Current:13.8A
Maximum Power Tolerance:±3%
Max System Voltage:1000V
Operating Temperature Min:-35℃
Operating Temperature Max:60℃
Folded Dimension:365*370*55mm
Open Dimension:1270*720*18mm
WHAT'S IN THE BOX
1x1x250W Folding Solar Mat
1x2m Cable
1xUSB Solar Controller
1xAnderson Plug
1xAlligator Clips
FEATURES
Latest 2020 Model
23% High Coversion Rate
Grade-A Monocrystalline Cell Panels
Matte PET surface, easy adhesion, stable structure and stamping resistance
High-density material with high light transmission, strong and aging resistance
Folding storage design, easy to carry
German Certification


View attachment 68983

The voltage looks ok but I thought it would produce more amps or is that normal??

The Aux was hovering around 14.3V after a while whick I know is in the ballpark for correct charging @ a max of about 14.7v

Just new to the whole set up as well so not sure if I am getting what I should out of the blanket?


Cheers.
Are you able to measure directly from the panel output lead with a multimeter?
 

Crackin

New Member
I'm going to say that you've been ripped off, like heaps of other people buying panels that aren't advertised properly.

A 200W mono solid panel with 17% cell efficiency is 1580 x 808mm. That's 1.276m2

Your '250W' panel supposedly has 23% cell efficiency, but is only 1270mm x 720mm. That's 0.914m2

A true 250W panel at 17% efficiency should be 1.595m2. Remove the 6% better efficiency factor for better efficiency and your panel should still be at least 1.499m2.

Your panel is more than likely a 150W, sold as a 250W.

Absolutely does my head in seeing this. I wrote a post a number of years ago about it, after finding my brother and a few mates had exactly the same experience - eBay solar panels; how to avoid being ripped off.

Test the panel under load, but I bet you never get more than 100W.

Aaron
Hi mate,

I've read your blog posts about solar panels and the correct sizes, all very interesting and useful!!

I have made up a spreadsheet comparing the panels I have been looking at and how their size compares to your guide so I have immediately discounted the ones that were barely half the advertised the power...........:rolleyes::rolleyes:

The Low energy dev ones from ebay are pretty close 0.1-9.7% difference in area. There are some from Tentworld who's actual area is lower than the correct area from your calculations so in theory should be more powerful than their advertised rating, but they are 2-3X the price of anythign else.

So to finally get to my question is it wise to base a purchase decision solely on the area and the accuracy of this to the correct power rating?

There is a semi flex 110W panel from Kings that is very close to your correct area and it is only 90$ so incredible value, do you have any experience with this brand or these panels?

Thanks
 

cam04

Well-Known Member
Hi mate,

I've read your blog posts about solar panels and the correct sizes, all very interesting and useful!!

I have made up a spreadsheet comparing the panels I have been looking at and how their size compares to your guide so I have immediately discounted the ones that were barely half the advertised the power...........:rolleyes::rolleyes:

The Low energy dev ones from ebay are pretty close 0.1-9.7% difference in area. There are some from Tentworld who's actual area is lower than the correct area from your calculations so in theory should be more powerful than their advertised rating, but they are 2-3X the price of anythign else.

So to finally get to my question is it wise to base a purchase decision solely on the area and the accuracy of this to the correct power rating?

There is a semi flex 110W panel from Kings that is very close to your correct area and it is only 90$ so incredible value, do you have any experience with this brand or these panels?

Thanks
I have a kings 160 semi flexible. It cranks. I haven’t bothered checking the wattage etc. Good value. I’m off on another week’s camping in a few days, I’ll try to remember to plug in a watt meter and have a look.
 

RBJET

Well-Known Member
I'd just purchase the biggest panel that fits where you want to stick it.
Mine were eBay cheapies ($60ea) and were advertised at a higher wattage for their dimensions.
I've had one fitted on my canopy for a few years now and it pumps out a solid 6 amps in the right conditions.
 

Komang

Active Member
In my experience it the solar controler
If I using the standart pwm controler ie ebay cheap one it will pump the max solar wattage can produce.
But when I plug in the smart solar charge ie mppt victron it only produce what the safe wattage the controler think for the load (same solar panel) if the load/battery flat it will pump max watt the panel can produce
 

Aaron Schubert

Moderator
Hi mate,

I've read your blog posts about solar panels and the correct sizes, all very interesting and useful!!

I have made up a spreadsheet comparing the panels I have been looking at and how their size compares to your guide so I have immediately discounted the ones that were barely half the advertised the power...........:rolleyes::rolleyes:

The Low energy dev ones from ebay are pretty close 0.1-9.7% difference in area. There are some from Tentworld who's actual area is lower than the correct area from your calculations so in theory should be more powerful than their advertised rating, but they are 2-3X the price of anythign else.

So to finally get to my question is it wise to base a purchase decision solely on the area and the accuracy of this to the correct power rating?

There is a semi flex 110W panel from Kings that is very close to your correct area and it is only 90$ so incredible value, do you have any experience with this brand or these panels?

Thanks

You won't find a quality solar panel on the market that is advertised as a wattage that is higher than its physical size can allow. The top tier products (Enerdrive, Victron, Redarc etc) will all be the correct size for their wattage, which speaks volumes.

Kings gear is cheap, but it does work and in many cases is as good, or better than what you'd get at the bottom of the barrel from eBay.

I would avoid mounting flexi panels unless they have good air flow, as they have a habit of failing
Aaron
 
Top