See , the way I check for the charge state of a flooded lead acid battery is to check the open-circuit voltage with meter , then take off the caps and check the colour and consistency of the electrodes . Fully charged flooded lead-acid battery should have more than 12.5v and dark-grey to almost matt-black anode and a brownish cathode . None to negligible white powdery deposits(sulfate) may be there on the electrodes . Colour & water level should be consistent across all the cells . Each cell should measure around 2.1v fully charged (measured by inserting meter's probe into each cell to reach the cathode) . After this you can measure the specific-gravity of the electrolyte with hygrometer too . I learned all this faltu work hands on maintaining banks of batteries of various types for work .
On examining this and other vehicle's batteries I found two defects . 1) The colour of the anode on 2-4 of the cells would remain a lighter grey colour after on-vehicle charging . 2) There would be large amount of white deposits(sulpate) on 2-4 cells . This indicates a improper formatting of the battery, imbalanced charging across the cells and surface-charge . A new lead-acid battery needs to be formatted by fully charging and then discharging to safe discharge depth atleast ten cycles . Battery should be maintained on trickle charging whenever not in use for long time, specially in hot climates . Also from time to time (say in 1-2 months) of use, the battery should be put on an equalising charge of more than 14.5v for about 2 hours to eliminate excess sulfate formation on the electrodes, equalising the charge state across the cells and prevent electrolyte stratification . Electrolyte level should be maintained above the electrodes, by addition of water if necessary after the charging is complete . So you can safely pull my leg that I am a bit too finicky about batteries .
This is the charging voltage I get at 1/4 throttle at idle and battery connected . Ok, no ?