AC300 PV input decreases after shading

Product Discussion BLUETTI AC Series
1

Hello,
New AC300 and just hooked up 1 of my 2 legs of Solar input and noticed an issue of my PV wattage unable to get back up to wattage after a shading event. So is there a problem with the MPPT unit unable to reset the VI curve?
Here is what happened specifically:
Environment: Panels are fixed and did not move at all. It’s hot about 102 heat index ,so I expect a slight drop in power from 1200 watts. Latest Firmware on AC300 and batteries (were at 50%).

  1. First time I Plugged in 3 x 450 watt panels and was receiving about 870-930 watts around 3pm.
  2. around 3:30pm a dark cloud goes by, knocks PV input to 190 watts.
  3. Full Sun comes back and only receiving 520-600 Watts of PV Input. (around 4pm).
  4. Tried a reset (but system would not allow due to PV still being plugged in).
  5. Changed the PV input from PV to Other and then back again.
  6. Solar input back up to 900 watts. (around 4:15pm).

Question: Is there a problem with my AC 300 that the wattage does not recover after a shading event? Or is there a long delay (greater than 30 minutes?) for it to reset the VI curve or is it something else completely?
Thank you,
William

2

I have an AC300 (using both pv inputs, or both mppts) and have never had that happen to me. My experience is that as soon as the cloud passes the watts go right back up. I never did a firmware update after receiving it. If you want I can look up what firmware it’s running.

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3

Thanks @MontAnna ,
I am going to see what happens after I get the 2 leg connected (in the process of building that support). I will monitor the situation on the 1st leg and if it happens again, I will record the numbers. We are about to have a series of rainy afternoons, so my data will be more solid if it happens again. (No need to look up the firmware, I don’t think you can use older versions, anyhow).
Again, Thank you.

4

I would also suggest since you are currently only using one leg of the PV input, try the other one… from my understanding each input uses an independent MPPT controller, so you might be able to isolate whether there is a problem with one of them.

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5

Off the top of my head as an alternative solution (you’ll know more with more testing!) it might be possible that the visible cloud had a higher cirrus or some kind of haze following it, where the irradiance simply wasn’t as great after the cloud passed as it was before. Would be darn hard to detect with the naked eye, too.

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6

Ok, so it appears after an AC300 restart that evening, helped. The next day, the system seemed to be behaving as expected. In fact, I have been receiving 1150 to 1220 watts on one pv leg (for 4+ hrs and when a dark storm cloud brings the watts below 200 watts, the wattage increases to expected levels when the sun comes back out. Excited to put this product to good use when the second PV leg is attached! I guess the reboot helped. I am unsure. I was skeptical on getting anywhere near 1200 watts due to the hot Florida sun. Thanks for the replies!

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