Have been running an experiment on the solar testbed. I kept a regular household LED bulb running 24 / 7 for over a week, just to watch the graphs go up and down. The light draws maybe 10W and the controller maybe another 10W. We have had a long streak of cloudy days and I noticed the light was off this morning. Checking the VRM it seems that it has been off for 12 hours. The inverter is also off. Looking at the graph it seems the battery was gradually drained, then it fell off of a cliff sometime during the night. I’m going to leave everything as is a see what happens when the sun comes back out, perhaps tomorrow.

Update: I had the Raspberry Pi which sends data to the VRM plugged into a USB port on the inverter. Very convenient except that when the battery gets low, the data logging stops. For now I have plugged the Pi into the wall so that logging continues. I suppose once the battery bottoms out there is no real point in logging. I’ll probably plug the Pi back into the inverter when the sun comes back out.