posted 11 months ago
Like anything else in the real world, capacitors have physical properties and limits. The main ones to pay attention to are the energy in to store a charge, the internal impedance (resistance) of the capacitor, the leakage over time, and the energy available on discharge. Add everything together to get the usable storage potential. That number will always be less than what went in.
A capacitor in a circuit is a load. If you found a source telling you otherwise, my advice would be to treat that source as unreliable. You can measure all of the variables and do your own research, or you can look up some better-quality information on how capacitors work. Plenty of books out there, as well as online resources (search for direct current, insertion loss, and capacitance to get started). Hope this helps!