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.
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.
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.
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.
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.
I have an Elite 200 with two 200W solar panels (all Bluetti). I noticed that with both panels connected (in parallel, with a Bluetti-supplied connector), I get about 175W of charging. However, when I only connect ONE panel, I get about 150W of power. Shouldn’t I be getting roughly TWICE the charging from TWO panels?
welcome to the bluetti community forum, thanks for your question.
When connecting Panels in parallel, they independent from each other, means shadows etc. arent a big problem. The Elite 200 V2 have a 20A MPPT if i remember right, this should also enough. A PV200 Panel have max 9,7A so two of them are under the 20A.
Maybe you can show us, how you connect them? When you have kinda the same power with one Panel even when you connect two, you maybe connect both panels wrong with each other.
@bmc123456 The primary reason for this is; At <30VDC input (VoC of the panel) the Elite limits input to 8.2A, at over 30VDC you can charge up to 20A.
A nominal 12V solar panel rule of thumb is 5A per 100W in good conditions. Your 200W panels will be roughly 10A per panel, however as the VoC in parallel is less than 30VDC the Elite limits input to 8.2A, no matter how many panels you connect.
The only way to utilise the total of your 2 panel’s best output is to connect them in series, which adds the Voc of each panel, or roughly 45VDC. The amps input in series is roughly 10-11A, which should, in reasonable conditions, give you between 300W and close to 400W.
Also, the best case scenario for solar into the Elite is; 2 strings of 2 x 200W panels in parallel, then connect the 2 strings in series. The simplified math is 2 x 20W in parallel = Voc 24V @ 20A = 400W. Then 2 x parallel strings in series = Voc 48V @ 20A = 800W. Note: doing this with 250W panels, in my opinion is ok as the extra amps will be absorbed by the Elite’s MPPT, but in less than perfect sunlight, you will get better output. Do not exceed the 60VDC solar Voc hard limit. i.e. 3 panels in series is TOO high.
Really good explanation, thanks. I have seen comments about the Elite’s 60V limit and wondered how it would be possible to get the best out of it for solar charging.
@Ktt
BLUETTI has previously offered rigid solar panels as part of balcony solar system line for DE market. However, due to the significant increase in tariffs and logistics costs (especially because rigid panels are heavy), this might be challenging to implement globally.
But still thank you for your expectations for BLUETTI! We truly appreciate your support and ideas.