Hi, I have a MultiPlus II 24/3000 in an ESS setup with 800WP and 200Ah "drop in" LiFePo4 batteries which has been working well for about six months now. When the grid is lost (either deliberately in testing, or when we've had power cuts) it has always maintained my essential loads (which is my office.)
Yesterday however, we had a thunderstorm and the power was out for about half an hour. This time, power to the essential loads were lost too, for the duration of the power outage. There had been a low battery warning earlier in the afternoon but the voltage seemed well above 24V (above 26V actually) at the time of the outage so I couldn't see why the inverter would fail to power the essential loads?
In addition, there was no "grid lost" alarm, despite the grid having been down for half an hour; when I manually caused grid loss this morning with the AC isolator everything worked as expected and an appropriate alarm was raised. Here are a few graphs from yesterday, showing the power outage from about 19:32 to 20:00 or so:
Any ideas?