Oh I am very sure there are much better batteries these days than 10 years ago. I have not looked into batteries, I am afraid if I do it will cost me more, as I will want to replace the dinosaurs in the system...... I can already see a huge difference in the panels, with the older Canadian panels I never ever made 11kw in February........ I love the Sol-Ark, it is a massive improvement over the old Outback........ I imagine that maybe this year I will start looking at batteries and see if I can improve my capabilities....... Right now, overnight to the next day is not really a big issue, but if the next few days are cloudy I am going to have some problems I am sure.Looks like yours are lead-acid batteries so they only want to cycle about 50% for best life. Yours are doing great. When you do have to replace them, there are much better alternatives now.
BTW........ just as a side note, I have a 40kw Cummins propane generator. Yes, I can run the entire compound and all the heat pumps, air cons, everything from a to z. I have a 500 gallon, or that capacity tank..... now that converts I don't know, but I could run probably 5-7 days total................. But if you are smart, and sometimes I think I might be on occasion, you would not run the gen continuously, maybe a hour or two here and there, keep fridges and freezers cold, and then off. Also, I THINK we hooked up the gen set to charge the batteries......... But honestly, I have to check on that and how to do it, since I have not done so...... now, if I can indeed charge the batteries back with the Gen Set, and I should be able to, then that solves some cloudy day issues....... I am going to have to check on that to see.........