My battery system is now fully functional after a bit of tweaking and testing. There was one battery unit that was behaving a bit odd, and after a full charge it seems to have performed self capacity test (it discharged and recharged). I did three tests setting the lower limits to 40%, 20%, and 30% and it worked well powering all of the house loads.

When it is put into full backup mode it can charge the batteries from the grid. In one of the flow charts you can see about a 15kw charge rate, thus charging the 40kwh batteries in about 3 hours.

My typical house draw on the ‘generator panels’ is in the 4-5kw continuous, so 8-10 hours of load time. A typical sunny day will net about 120kwh of solar production so more than enough to charge the batteries back to 100%. A cloudy winter day will see much less production, often in the 20-40kwh.

Next up is integration of a generator using the batteries as powerbanks so the genset doesn’t have to run 100% of the time when we are off-grid.