By aluminium I mean any solar panel surrounded by aluminium framing such as (https://aussietraveller.com.au/cdn/shop/products/ATSP_160WFLD.png?v=1737689946&width=2048)
rather than the fabric surround of a lightwieght folding panel such as (https://www.plusrite.com.au/wp-content/uploads/2023/09/200w-folding-solar-panel-SSP50-200S-scaled.jpg)
I was referring to aluminium due to the lighter weight, being on a static.
My concerns will relate to fully appreciating the VOC rating, as kindly pointed out by hnymann, charging my AC200L & B300K.
I’m a classic amateur diy bloke, but electricity terrifies me!
Cheers again.
Andy.
Great post!
Thank you.
I have 390 watt panes with a VOC of 37 on my AC300. I also live in a cold area. I have two sets of three planned. As of now I have only 5 of the six hooked up but have had 1.6 kw input max in the winter so far. I have another panel coming that was damaged in shipping.
Hi fellow solar enthusiasts, here is something interesting concerning over wattage without over panelling:
After weeks of little to no sun due to Northern Latitudes and being more overcast than usual, I was very pleased to notice that my 2 BLUETTI PV350’s rated at 350 Watts each maxed out at close to 900 watts today.
I took some photos from today showing a slightly lower wattage but still excellent.
Hi there hnyman et all.
My AC200L states ‘open circuit voltage’ 12-145 k-dc & max input power as 1,200 watts (15 amps).
As I contemplate getting my generator up & running, on this miserable, classically British, morning (overcaste & raining), I’m looking at solar panels.
One in particular that I’m pondering over is rated at 270 watts, with a max output of 20 volts.
So four of these and I get a max of 1080 watts coming in & a max of 80 volts.
I could even go one more?
Any comments ‘Oh knowledgeable ones’?
Andy.
Hi @AndyStuart !
The 20 Volts, is this the Open Circuit Voltage of the panel or the operating voltage? Its really important to always look at the Open Circuit voltage. When you powerstation is fully charged, this voltage will be present on the MPPT and its much higher then the operating voltage.
When you panel states a open circuit voltage of 20V, than you can connect 7 Panels in series without a problem (140V). AC200L only have one MPPT, means all of the panels needs to be in one series. If one of them covered in shadown, all of them suffer. So it may be smart to use less panels and more look that they all in the same Sun/Shadow zone.
Hope that helps
Erik
Thank you Erik.
So if 20 volts is the operating voltage for 1 panel then multiply by 4 (panels) & we get 80. Is this not the OCV?
Mind you, charging via my wee generator every couple of days is a doddle, at 2 quid a shot!
Andy.
Hi @AndyStuart !
Its a really important difference. When one panel have 20V operating voltage, then 4 in series is only the operating voltage too. As long your powerstation is charging, there is only 80V but as soon you unit is full, the ovc voltage takes it place. When this is too high, it kills your MPPT
Look for the highest voltage value on the panel and use this to calculate your setup.
greetings
Erik
Good for you!
This is probably due to the low temperature of the panels and the snow which reflects and concentrates the sun’s rays on the panels…
Hello Snips1.
Thanks for getting back too me.
I have noticed this added effect, and it usually starts in the AM, around the time of the suns’ zenith.
The colder temperatures around my part of the world in winter lately are daytime highs around -15 - 25C, nighttime lows minus 30C.
So if I have my panels angled and pointed in the right direction at the right time the resistance within the panels cells is lessened due to the cold temps, so the electrons move more efficiently therefore creating more power. Yet I am surprised by the amount of efficiency. I am looking at 10% or a little more “wow”.
In the past, I have only ever noticed around 2-4% increase.
I have been trying to keep an eye on the VOC of the panel when this is happening, but so far that hasn’t been a concern.
In summary, I can say that in winter we have shorter days in which to charge our batteries but colder temperatures to help increase the normal power output.
Happy Solaring
B
Here is a picture from the spot I usually look at my panels in the laneway.
This was taken Feb 15 after 4 days of storms. You can tell it has been cleaned up a little bit already.
