question

Hello Romeet. I think you could safely pick one of the standard settings for your batts. As 'Calcium/MF', they're likely AGM type, so see what available there. (In 12V, not 48V), the standard settings might be 14.4 Absorb and 13.8V Float. You can keep the algorithm as-is, but just tweak the V's if you desire.

In your diagram there may be a language/meaning thing involved too.. 2) Maximum V 13.8, I suspect refers to Float. And 5) Floating Voltage 12.8V seems more like a standing V than anything useful as a true charge float. But you could check that with the batt maker.

I haven't the app here to check what's available, but you may find additional options like 'Adaptive' or 'Battery Safe'. You could study up on them and delete if you want, but they'll only help unless you have special needs.

Note too that daily-cycling Pb's will always keep accepting some charge. 500Ah @ 48V is a substantial bank, and you may never see it down as low as 5A (~250W). The real world..

With 5x parallel batt strings, imbalance may eventually become an issue. And 'softer' charge settings may assist with that. Personal theory only, and of course you've still got to charge them over the day. If they need 'equalizing' I'd probably dodge doing that without close & constant supervision..

@JohnC Thank you so much for your response, i appreciate it. I am afraid i dont seem to be able to follow, esp the Floating Voltage and charging voltage points you have touched. i am attaching a picture of the battery label so it may give a clearer indication on what they probably mean with the values i posted ( could be i may have put up a confusing scene )

My concern with charging, and i agree with you that it probably may not be that low, is that i tested each and every battery ( all are brand new and hooked up together in one go- no mixing old and new ) to see if there was any that probably had issues and would keep requesting for a false charge due to some issues with it, none, all would reach floating volt when i tested them in a smaller 12V MPPT Scene and gave expected backup.

The batteries are fully charged, i had kept a custom value in maximum charge current to be not more than 50A ( though i would have preferred a smaller current to get a nice slow charge ) and my charging voltage id kept it at 57.6V and Floating Voltage at 51.2V ( all being direct multiplication for each battery values x 4 ).

I notice that even when the battery bank reaches the floating voltage of 51.2V and the output load being minimal at say 300W ( not more than 7-9A ) the controller keeps indicating that its on absorption and will keep charging the batteries at approx 30A.

i Monitored this for about 20 Minutes to see if the charging ( overcharging ) would stop in a bit maybe due to temp compensation or something, but it didn't. Fearing for my battery health, i have turned off the whole system and thought of asking for help here to see if i may be making any mistake in the values? or if i am overlooking some temp comp factor or some settling down concept?

do you reckon it may be offsetting some imbalance that the controller detects, like you mentioned above?

Thank you once again for your help and detailed response, i truly appreciate and am grateful for your efforts.