During my journey to electronics I came across several questions about capacitors.
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If we connect an empty capacitor to a fully charged re-chargeable battery, after the battery charged the capacitor, it then became empty (wires still connected and never touched), what will happen in this situation? Will the capacitor re-charge the battery? Or will its charge drop due to the battery’s internal resistance without charging it?
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If we replaced the battery with a charged capacitor (empty capacitor and charged capacitor with same values) what will happen in this situation?
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If we connect a charged capacitor and an empty capacitor and a charged battery all in parallel, what will happen?
Any help to clear my doubts is preciously appreciated.
Best Answer
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.