I have 2 Quattros supplied by a large lithium battery bank powering a boat. This morning batteries were around 90% SoC. At some point I realized we had no AC power--it was there and a few minutes later it was gone. There was nearly no AC load during this time. I accessed the Cerbo and found the inverters were "off." I switched them back to invert, and everything came back up. Nothing in the error log. I had a similar experience months ago, happened once, no idea what caused it, didn't happen again until today. Thoughts?