Capacitor loop charging
Any help to clear my doubts is preciously appreciated


Consider two tanks of water: -



Tank 1 is your fully charged battery and tank 2 is your capacitor. After a short while the levels will equalize. Tank 1 will have dropped its height a little bit in order to fill up tank 2 to a pretty high level. If you had a really massively big capacitor (tank 2) you might deplete tank 1 quite a lot.

Voltage = water level in each tank and tank cross sectional area (plan view) is equivalent to capacitance.

This pretty much applies to all mentioned scenarios.