Amperage Bell Curve for a severely discharged battery
Wattage Bell Curve for a severely discharged battery, but not nearly as pronounced as amperage droop.
High resistance is a discharged state is due to high resistance of a particular type of sulfation deposit on the plates. It is a bad sign of neglect and mistreatment.
kWh charge AND meaning AND, ampere hour charge efficiency DROPS OFF (less efficient) at low and high states of charge. Fight that with avoiding latticed sulfation formation and you have expressed the woes of 101% of cyclable battery users.