I am not completely sure I understand the Mate display--But that is OK. Let us approach it from a different direction.
You have a 225 AH @ 48 volt battery bank, and lets assume it is 50% charged and you want to get it back to full charge.
From an Amp*Hour point of view, batteries are pretty nearly 100% efficient (in terms of Amp*Hours out~AH in) (except for near 100% charge and equalization where efficiency can drop to near zero percent as you end up, mostly, converting electricity to heat plus hydrogen and oxygen gases).
- 225 AH * 0.50 to recharge = 112.5 AH to bring the battery bank back to "Full"
Watt*Hour wise, where batteries are 80% to 90% efficient at charging (energy vs Amp*Hours):
- 225 AH * 0.50 state of discharge * 59 volts charging * 1/0.80 eff = 8,297 WH = 8.3 kWH to recharge a 1/2 full bank
It looks like you are getting ~21 amps into the battery at that time of day (almost 10% rate of charge--that is good):
- 112.5 AH to recharge / 21 amps = 5.4 hours (plus 2-4 hours for Absorb)
But, you really need to add a few hours for Absorb charging (once the battery hits 59 volts is Absorb set point, and current will taper from Imax-charge to a few percent of battery AH capacity after 2-4 hours or so).
Of course, there is the question of how much load you have on the battery bank overnight--Is the battery bouncing between 50% and 75% state of charge, or between 75% and 100% state of charge (the second does not sound likely).
You can start the genset in the early AM and run it until you get to ~59 volts on the battery bank (that is the absorb transition point and the battery bank should be ~80-90% full). Then let the solar panels carry the charging during the rest of the day.
Or, you can start the genset in the evening (when you have loads and less than full battery bank--and somebody is home to operate the generator) to help get it back up to the ~59 volt Absorb point--then shut down. And let sun (or sun and generator) manage the rest of the charging the next day.
By the way, what is the generator kWatt rating and the Amp rating (and voltage set point) of your AC Battery charger?
Need to get a handle on the battery state of charge and where it tends to cycle during the 24 hour period. A battery monitor makes it easy, but an accurate hydrometer (if there is one) and logging data (AM before sun is up, and PM at sunset) for a pilot cell will be a great help. As will knowing your loads (AH/WH used) and charging (AH/WH from sun) (difference should be AH in/out of battery bank). The battery monitor will monitor AH in/out of the battery which is critical to understand right now.
Sorry to be such a pest--But I am not sure I understand your needs/operating conditions yet.