I have had my unit, AC200MAX, for over a year and just started using it and using the solar panels for charging. Just after about a week the unit was not recognizing the solar panels being plugged into the unit. The charger would work, but not the panels and I was getting an alarm that showed “030 Calibration Failure” code. I contacted Bluetti since I purchases it directly from them. I was contacted a couple of days later by Annie from support. We email back and forth several times with her wanting me to try other options, checking the firmware for updates, different charging methods, checking the panels and so on, as well as sending pics of the results. This went on for several emails until the next step was to return the unit. They sent return labels, and I took to FedEx on a Friday. By Thursday the following week my unit was back. I checked and the unit was working fine. I have not had a chance to run all day but so far so good. Annie told me that the mainboard was being replace. All in all my experience with her and the service department was great with no major issue. Thanks a lot.
MK