I thought I set the state of charge correctly to 100% when the battery was at float so confused why it’s still showing 60% still left on the shunt. the history shows only 227ah used. so am thinking its correct but i'd like to use the capacity down to 10-15%.
is one of my batteries defective? whats stopping the discharge? how can i get the full discharge down to 10-15% level ?
Well... none of the wiring in this photo is appropriate for a 12/1200 inverter, not to mention the -for lack of a better term- absolute spaghetti mess/fire hazard present in the rest of the wiring here, so personally I would advise first correcting the installation as a whole and then you can re-evaluate its performance after you've corrected the installation.
One cannot expect anything to perform as designed if it's not installed properly, so while it is possible that one of your batteries is defective, it's equally possible that the batteries are fine and it's just the nature of the installation in its current state that's to blame for the deficiencies in performance.
A good beginning resource for understanding electrical systems in general is Victron's Wiring Unlimited book, which is a free download: https://www.victronenergy.com/upload/documents/The_Wiring_Unlimited_book/43562-Wiring_Unlimited-pdf-en.pdf
After reading and understanding that book, you may be better equipped to correct the rest of the installation in accordance with the various installation manuals of the components that you have, or alternatively commission an experienced and reputable systems installer in your area to correct the installation and program everything appropriately.
