Thanks Talha bhai for sharing your experience with community here and thanks to all mates here who contributed to this post.
Well i was forced to purchase Millat 110 ( 80amp ) batteries due to budget issues as i already waisted my money on a single used Narada dry battery which didn't worked as planned :(.
My ignorance I assumed that I can change charging current level in a Chinese UPS (Invertex board) which i can't. Now my setup goes into backup mode (cutt off) in 15mins after an hour of load shedding while Max load is 100W at the moment so UPS is charging it at 10 amps which is above your formula.
Now i have to continue with this setup or have to purchase any configurable UPS which i don't thing possible in near future. 
Anyways I also flushed my abused AGS 100 battery ( in 1st pic ) and added new electrolyte to it. Its working great so far even better then Narada battery :). Its weird that AGS battery's 3 cells have dead level gravity in fully charged state while other 3 cells have somewhat near dead level.