We've recently had a solar array and Powerwall 2 installed. After applying through my energy provider to change to a feed in plan, I've been instructed that they need to upgrade my electrical meter. To do this they've asked me to shut down my solar system until the work has been done, presumably so that the meter can be worked on safely in case I'm not home when the work is done.
Instead of losing the advantages of my new solar system and Powerwall for up to 30 days while I wait for that work to be done, before I left the house this morning, I have simply isolated the house from the meter (and grid) by opening the grid supply breaker. This is confirmed in the Powerwall app by the "Grid" icon being crossed out and the Powerwall entering "Backup" mode.
The Powerwall is configured in "self powered" mode.
The following output from the app tells the story: https://s3-ap-southeast-2.amazonaws.com/ajh-web-public/Screenshot_201805...
We woke up at point 1 and had warm showers, the spike is our water heater.
At point 2 the Powerwall hit 15% charge which was my reserve amount, you can see that at this time load shifted to grid supply as expected
At point 3 I configured the Powerwall to zero reserve and then opened the grid supply circuit breaker on my switchboard. Coincidentally we started receiving power from our solar array. I checked the appliances were running fine from the battery before leaving the house. The battery was at around 15% charged and charging from the solar array. You can see we had a nice clear day and were getting good supply from the solar inverter.
At point 4 The battery reached 100% charge and as I would later find out we at least momentarily lost steady supply to the house.
Between point 4 and point 5 my solar inverter output was zero according to the Tesla app and the metrics directly from the inverter itself. During this time there was no reason to assume there was any loss of solar input to the inverter, it was a nice clear and mild day. Obviously with no load the inverter cannot provide power. There was a small standby load at that time, but that seems to have been drawn from the battery.
At point 5 the battery drew some charge from the solar inverter. After recharging, the inverter continued to provide the output to cover the standby load being drawn from the house, up until point 6 when we ran out of daylight.
When I got home at point 7, the house had power being drawn from the Powerwall. I saw my digital clocks flashing a time that indicated they had lost power and powered back on at the same time Powerwall reached 100% charge, however the fact that the clocks were on at all indicates that they had a steady supply from the Powerwall since then. I closed the grid supply circuit breaker at this time and turned on the washing machine and microwaved some dinner (the spike just after point 7).
My question is, would a short power loss be expected when the battery reached 100% charge in this situation? Is the Powerwall only able to fully handle sudden shifts in loads when there is a grid supply?