Thanks Plonkster, I hadn’t thought about is that way. They’re still 12V batteries and I agree that 12,8 is pretty good.
That said, I set the system to keep batteries charged last light night like you and Richard suggested, and left it there overnight. (it was already basically full when I did this)
I measured this morning and these are the results:
1st battery (which is the + of the 48V) = 13.25V (190Ah)
2nd battery = 13.30V (190Ah)
3rd battery = 13.68V (200Ah)
4th battery (which is the - of the 48V) = 13.60V (200Ah)
Me thinks this is still very good.
The moment I switched back to optimized with battery life, the volts dropped immediately to 52 something as per below screenshot. I supposed I didn’t think a small load like this would make the volt reading drop that far. I think it is still remnants of the olden days when I started playing with batteries and dual battery systems when most of us thought volts and SOC is the same thing.