I've got a BLUETTI AC200MAX solar station with five Renogy 200W panels connected in series. Lately, I've been seeing pretty low output—about 250W max around noon on clear days with everything angled correctly. I tried testing each panel individually to see if one was faulty, and when I washed them down with a hose, they all registered around 130W. However, when I rinsed them with cold water while they were all connected, the output shot up to 850W, but then gradually fell back down as the panels heated up again. On a 29°C day, my temperature probe showed the panels were at 65°C, so they weren't excessively hot. I have them set up with a 50ft 10 AWG solar cable extension, which might be a factor. I'm confused about why the cooling effect of the water made such a drastic difference in output and would love suggestions on how to improve my panel performance.
3 Answers
It almost sounds like you might have poor connection points. When you rinsed the panels, the water could've temporarily improved the contact until it evaporated. I'd suggest disconnecting everything and inspecting all the connections to make sure they're clean and tight. This could really help with your output problems!
It sounds like there might be an issue with your wiring, especially since the temperature drop from cooling the panels had such an effect. Typically, you should see a drop in output due to heat, but not that drastic! Check your extension cable for any faults or loose connections, they can definitely impact performance. Also, when you connected two panels and only got 160W instead of around 240W, it suggests one might be having issues. Try mixing up your pairs to isolate any potential faults in specific panels.
Yeah, I'd second that! Testing different combinations can help you pinpoint where the issue might lie.
You're not likely overheating the panels if they're at 65°C in only 29°C weather, so I suspect there's more to it. You should monitor the solar input voltage on your AC200MAX when troubleshooting. Label your panels and track which ones you connect together; there might be a bad join causing a drop in output. The extension cable length could also factor in, so consider testing with a shorter cable while you troubleshoot. If it’s not the cable, keep an eye out for a specific panel causing issues. Good luck!
Totally agree! Isolation is key here. If it's not the cable, definitely focus on specific panels.
That makes a lot of sense! Water could definitely help close gaps temporarily, worth checking those connections!