I went to “advanced settings” and went to DC input source and selected PV.
No change in the solar power inputs - still at 138 W with both panels. It says max grid input is 12 amps - it appears I’m getting around 8, though.
So this thing is designed to charge very, very slowly?
“I read that at around 16V or so its limited to 8.2A at max. In your case the default non-advanced mode would throttle to 8.2A below 30V which is likely what you are experiencing. Note anything below 16V will be 8A regardless of advanced or non-advanced mode.”
Having to worry about this big powerbank getting discharged with 2 200 watts of solar power just by running Starlink and a computer plus odds and ends in full sunlight is really disappointing! I don’t know how other people are getting such high inputs.
I do see that connecting the solar panels in series will boost the voltage up.
Did you disconnect and reconnect the PV/solar (From the powerstation end) after doing so or leave it plugged in the entire time after making the changes?
No I didn’t. I just unplugged it and it’s the same.
I connected them in series - Apparently, I need to hit 35 V. AI says that connecting 2 200-volt panels together in series should get them to 35-40 volts, and it;s getting 33-34 volts!
The power flowing into the Bluetti is the same - 121 w - I guess it’s close but just missing the mark.
If that’s the solution that’s fine - I’ll get another portable solar array.
Running in series is an effective way to bypass the 30V throttling since you’ll generally be above that under optimal conditions. Keep in mind that when you run them in series the same current flows through both panels. This means that even if one panel is completely in the Sun and only 25% of one panel is shaded, but that 25% caused the current on that panel to dip to say 3A, your array is now 3A, and your power would be 16-20V@3A or around 45-60W. TLDR - Make sure BOTH panels are not shaded obviously. Shading just 1 panel kills power for both.
If you are getting only 121 watts and its at 33V minimum, that is only 3.6A (121/33= 3.6). So in series the entire array is only 3.6A?! If thats in full sun, something is dragging it down. One panel is shaded or misaligned. There’s dust or debris on one of them etc. Otherwise that is NOT normal.
Also both need perfect alignment as well. Point panel #1 at the Sun and panel #2 away from the Sun, the array will be the LOWEST current of the two, so if its 0A due to the fact you are facing the 2nd panel away from the Sun, you’ll get nothing. Group is only as fast as its slowest member type of deal. I say this because in your video I noticed you had one panel facing one way and another facing at a different angle. 3.6A would be the lowest amp rating of the panel you have facing the MOST away from the Sun for example. So if I had one panel perfectly aligned getting 9A and the 2nd panel facing at an unoptimal angle only getting 1A, if I joined them in series, I’m going to get just 1A.
Another thing is in parallel your panel current should be doubling and the fact that is not leads me to believe perhaps the MPPT algorithm is not making adjustments to the changes you made. If you lay your panels flat and say you get 17V and 8A for each of them when laid flat, if you connect them in parallel you should get around 17V and 16A. A firmware update may be available to fix this irregularity perhaps. I am assuming of course the cables and the connectors are rated to handle 16A in the configuration and not the 8A limit of the XT60 connector as stated before. I’m not 100% on all of this just food for thought. So is the array in parallel truly limited to 8A based on what cables and connectors you have is what I’m saying essentially. If the cables and the XT60 ARE rated to handle the 20A then possibly a firmware update can fix this. If its a physical limitation, then no software update will ever fix it. You can do your part by eliminating outside variables such as making sure both panels are not shaded and are perfectly aligned.
I vote for something wrong. Both panels were flat on the ground pointing just about straight up at the sun. The voltage just went over 35 and the watts remained the same - 119.
I assume the cables that came with Bluetti are OK. There is one that is attached in series from one 200W panel to the other…They don’t seem different in size to the Bluetti’s, though.
Thanks - I will get in touch with technical support.
When laid flat your power output should be the trigonometric SIN of whatever the altitude of the Sun is minus around 10%. So if the Sun is at 50 degrees currently you will get SIN(50) or 0.76 . 76 - 10 = 66% power. For a 200 watt panel that should net you at least 125W. Assuming panel is not shaded, not dirty, no haze in sky, etc. obviously. For every 10 degrees F above 77F the panel may lose about 2% efficiency. Assume your panel is 140 degrees. 63 degree difference would be 6.3X2 or another 12% loss. 66-12 would be 54% or 108 watts from a single panel laid flat. In other words a 140 degree F solar panel will produce 12% less power than one at 77 degrees F.
Right. Not even close…
No harm no foul contacting support! Something seems awry when you told me the newer panel was only pushing 55W compared to the other one at 87W. Best of luck.
Thanks for all your help - I have learned a lot. I will update when I know more and if you or anyone else has any more ideas I am all ears.
I still come back to this forum post
““I am asking because I am not sure if there is something wrong with my PV200 panel. It has been peaking at only about 135 to 140 watts output in direct sun, which equates to only about 65 to 70 percent in pretty good conditions.”
That’s the best I get from two panels. There’s got to be a way to do better. :)
Hi @Cort, Thank you for the information provided. We have reviewed it and consider the situation to be normal.
There are many factors affecting solar input. Could you please let us know roughly where you are located? Please check the local lighting conditions. In most areas, it is difficult to achieve an 80% solar energy conversion rate.
In addition to environmental factors, the installation should also be checked. The solar panel should be tilted and oriented vertically to maximize solar absorption. Meanwhile, please clean the panel surface regularly. Humidity can also have an impact.
Finally, please inspect the XT60-MC4 connector for oxidation or looseness, and ensure the connection cable length does not exceed 10 meters (excessive length may cause a voltage drop ≥3%).
Thank you to @Selfmadestrom and @sealy1986 for their attention to and resolution of this matter.
1 Like
Flagstaff, Arizona - I will clean them and see what happens.
Meanwhile, I asked two AI engines, at midday in June in Flagstaff, Arizona, how much energy two 200-watt portable solar panels should produce.
AI Perplexity - On a clear June midday in Flagstaff, expect your two 200-watt portable solar panels to produce about 315 watts combined—possibly a bit more under ideal conditions, or a bit less if factors like heat or panel angle are suboptimal
Chat GPT - At midday on a clear June day in Flagstaff, Arizona, solar conditions are excellent due to the high elevation (~7,000 ft) and low humidity, which reduces atmospheric attenuation of sunlight.
Estimate of Solar Power Output
Two 200-watt portable solar panels (total: 400W rated power) can be expected to perform near their rated capacity under ideal conditions. Here’s how to estimate real-world output:
| Condition | Expected Output |
|---|---|
| Optimal (cool, clean, angled) | 360 W |
| Realistic Midday Average | 320–340 W |
| Suboptimal (hot, flat, dusty) | 280–300 W |
I’m getting less than half of what they consider to be “suboptimal” results.
I will clean them and see what happens.
I’d read somewhere that dirt didn’t really affect solar panels so I never cleaned them.
When I cleaned them - the power jumped up from 55 watts to about 115 watts and then up to 165 watts at 4 pm in a somewhat cloudy afternoon (!!!) - but then it went back down to 55 (maybe because it was cloudier). The light is too variable right now, but there’s clearly hope.
I will check back when I have clearer skies
Thanks for the idea. :)
Absolutely dirt can kill the panel’s performance. I glazed over your video and didn’t pay close attention, but now rewatching it again your panel was CAKED! The panel doesn’t even have to be entirely caked, just caked in the wrong spots where the bypass diodes would kick in. I’ve read as much as 25%. So 2 panels would be 50% loss in power which is at max 200 watts. You said the highest you got was around 180’ish if I remember. Makes perfect sense.
Things were looking good, but no dice. Cleaned panels are putting out 125 watts again in full sun at midday. Very confusing!
And when you separate them what is the volts + amps of each “clean” panel. Also what is the latitude of your current location?
48 and 56; latitude - 35.198284