Page 71 of manual towards bottom..
For FLA and VRLA: Nominal voltage of the battery 42 V to 52 V adjustable in 2 V steps;
default setting: 48 V. (I tried that the other day for a moment and it worked. Went to 42 and back up)
We have sun coming after rain this week (Friday) So, Saturday and beyond I can test this application.
So in my limited knowledge of solar.....advice is always given to go past 12, 24 and 36 to a 48 volt system if your budget allows. That being said 42 volts is much better than the lower battery voltage systems..Logical?
End goal: Get the 2 batteries to charge fully rather than the 3 cells in each hindering that charging and suffer with a few less volts. Later this year replace bad cells...