I have a Phoenix 12/500 which I tried to use with a 500W load. The app showed that the inverter was under high load but the voltage drop on my battery was significant, it went from 11.5V to 10.1 or lower.
So at that point the undervolt protection kicked in. After this the inverter seems to be stuck in the 'OFF' state. I have tried now to charge the battery to at least 13V hoping the inverter would turn back on, but no success so far.
I saw the 'charge detect' setting that is on 14V on factory settings, and tried to lower this to 13V, but that didn't help either. Is there any way I can reset the transformer from this error state? The battery voltage should be high enough now to use it again with the inverter.