Its always inverter 1 in my observation. Not sure why.
I have noticed its pretty evenly split when I run my clothes dryer. 54,46 or so
It happens on AC as well.
I stopped paying attention to it, Never had an overload with 2 yet.
I have a 48v incandescent light bulb run across the breaker on a normally open push button switch like yours., if there is a voltage difference between the 2 lugs of the breaker(off), the light lights up. Once there is a insignificant voltage difference, the light goes out and caps are charged.
That picture sure looks like lipo. Are you sure they are 18650's?
If I were you, and they were 18650s, I would rip them all apart and disassemble everything.
We are talking about 6000 individual 18650 batteries.....
I would capacity test every one of them and make 3.6v banks out of them and...