Interesting Observations During Power Outage with Solar and Powerwalls

[RKCRLR]

Summertime in the Sierra Nevada foothills means frequent power outages. I've made an interesting observation during my last outage.
I have an older 4kW string system and a newer 6kW Enphase IQ7 microinverter system. Last year during power outages when I had 2 Powerwalls and prior to lowering my off-grid frequency shifting from 65 Hz to 62(?) Hz my Powerwalls would get down to about 92% before the solar would start recharging the Powerwalls and then get close to 100% and cycle between these percentages.
I've since added a 3rd Powerwall, lowered my frequency shift to 62(?) Hz, and had some firmware updates. In my most recent outage I observed that my Powerwalls went down to about 96% and then went back up to 98% and stayed there modulating the solar. By modulating I mean the solar generation was going on and off but the Powerwall charge percentage remained at 98%. I suspect I was basically running of my Enphase system since my string system goes offline at the drop of a hat. I was curious to see what happened as the sun set but the power came on at about 4pm so I never got a chance. Don't know what changes made the difference.

 

[jrweiss98020]

I also have an Enphase system - 35 panels and 2 Powerwalls. I just tested the off-grid mode, and the turnover was seamless. Max freq was 62.4, UPSes did not trigger. Once the Powerwalls got down to 98%, solar cycled in again, keeping Powerwall level 96-98%. Looks like the latest firmware (22.18.3) has it wired (pun intended).