Ok, the battery has been online for a few weeks now. Haven't had any problems with it at all. During these long nights, we can't stay off grid from sunset to sunrise, mostly because we burn through about 50-60% from the time we get home, (usually 5pm) until I go to bed around 11pm. PV generation usually stops by 4pm, and starts about 8am.
Most of that drain is from one or two TV's, frig, several lights, and occasional high power items like toaster oven or microwave, even though they're not on that long. After we go to bed, the max load is about 150W, mostly from the frig running about 20 minutes of an hour. Then there's a couple alarm clocks, modem and a CPAP machine. So from 11pm to 6am, when we get up, the drain is usually 20-35%.
So, from dusk until dawn it would almost completely drain unless I allow the grid to charge it about 10% before I go to bed. I don't want it to get below 20% if I can avoid it, the lowest it's got is maybe 25%. I imagine during the spring and summer, we might be able to get thru the night without any grid charging.
If there's sufficient sunshine it takes about 2.5 hours to charge from 30% to 100%, the last half hour is when the BMS throttles back to about 9-10A when it gets to 95%. Max charge is limited to 50A, which can happen with bright sunshine. This time of year, if there is bright sunshine first thing in the morning it really starts charging about 9am and usually finishes before noon.
Generation per day obviously has increased since the batt needs charging, the sunny day average is about 3KWh/day. Of course not all days are sunny, so we're lucky to get half a KWh then. My wife was home last Friday working from home, and since it was sunny and she did a couple loads of laundry, we got about 5.6KWh, the most this system's produced since it came online in April. The most at any one time was right at the array's rated power, or 3.6KW, that was at max charge of 50A, and a 700W load.
So moral of this long story is..
I need more batteries!
