Whats the difference between a 12v and the 24v capacitor?

Question

Whats the difference between a 12v and the 24v capacitor?

Answer 1

Those are the "Working Volts" of the cap meaning that's the maximum voltage they will operate at.

If you put 12 volts into a 24 volt cap, all you will get out is 12 volts.

Answer 2

Usually the voltage rating on a capacitor is the maximum voltage. If you exceed it, the part may be damaged.

If this is a super capacitor, the number MAY be the nominal operating voltage. Read the data sheet to be sure.

Note that auto battery voltage is 14 volts when being charged. So you should not use a 12 volt capacitor in this application.