The issue was that I was running the printer, and only the printer, on the EcoFlow and in ~2 weeks of printing the EcoFlow killed the AC output 3 times.
I didn’t know why as there were no large loads - definitely not over the rated 1800W.
Today I had a theory that the input charging + output AC > 1800W = overload.
I put a heat gun + filament dryer + on it to a 1500W load and then discharged it down to 40%, then plugged it in and charged at 1500W - it charged at 1500W and ran the 1500W load for 10+ minutes without anything failing or overload tripping.
That said I did notice that when it started charging the heat gun appeared to slow down greatly - but I didn’t have my multimeter handy to test the output voltage of the unit. None of the electronics I had plugged in complained though.
So I just tried reproducing what I thought the actual issue was - the system kicking on the charge while running the printer [90 to 100w normally, spikes to 300] and was able to capture it on video.
The video is for EcoFlow - I only shared it here to illustrate what I was saying. To be clear I am not trying to throw shade at EcoFlow - and I think the limitation is not surprising, it just seems to be undocumented.
I have it bypassing the battery/inverter for running the output - but it seems when the charge kicks on - that bypass doesn’t function. I can understand from a technical and electrical engineering standpoint why that would be. I can also understand why they would use the inverter to to handle the AC->DC rectification for charging and how that would limit the output of the inverter during charging.
Just to be extra clear - the limitations of the unit are not surprising beyond that they appear to be wholly undocumented.
If the owner’s manual stated something like, “While using the unit in UPS mode, the system will occasionally charge to keep the batteries full and during charging AC output will be reduced by the wattage being used to charge the batteries,” or something similar.
There’s probably a way better way to word it that would make more sense.
All in all - at this point - I’m only waiting on EcoFlow to either confirm this is working as intended [or] that there’s a bug in the firmware that will be addressed in the future.
I think it would be possible for them to update the firmware so that it prioritizes the load over charging when charge wattage+ac load > 1800w, but I can’t say for sure.
Given the choice - I would rather it charge slower than I set and it keeps the AC load live, than kill the AC load.
And no, I don’t have x-boost on.