Experiment 6 - Comparison Capacitor - Battery

In the last experiments, a comparison between a capacitor and a battery was drawn several times. Both store electric energy. What is the difference of their capacity? You learn this here.

A standard 9V battery stores 500 mAh. It is able to...

• supply 500 mA for one hour. (A torch with a 4.5 W light bulb lights up 3600 seconds long.)

A 100 μF electrolytic capacitor charged with 9 V is able to...

• supply 0.9 mA for one second. (A torch with a 4.5 W light bulb lights up 0.0018 seconds long.)

Therefore, to replace the 9 V battery, you need a capacitor with 200 farad...or...2 million 100 μF capacitors!

A 9V battery (left) and an electrolytic capacitor (right). (Enlarge)

Symbol 9 V battery.

Symbol electrolytic capacitor.

Batteries can therefore not be readily replaced by capacitors.

But how to combine two million capacitors? This you see in the next experiment.