Regarding the polarity of electrolytic capacitors, pay attention to observe that the symbol "-" on the side of the electrolytic capacitor indicates the negative pole, and the symbol "+" indicates the positive pole. If the positive and negative poles are not marked on the electrolytic capacitor, it can also be judged according to the length of its pins. The long pin is the positive pole, and the short pin is the negative pole.

Feature 1: The capacitance per unit volume is extremely large, dozens to hundreds of times larger than that of other types of capacitors.

Feature 2: The rated capacitance can be made extremely large. It is easy to achieve a capacitance of tens of thousands of μF or even several farads (but it cannot be compared with double-layer capacitors).

Feature 3: It has an overwhelming price advantage compared with other types of capacitors. This is because the materials used in the composition of electrolytic capacitors are all common industrial materials, such as aluminum, etc. The equipment used to manufacture electrolytic capacitors is also common industrial equipment, which can be mass-produced, resulting in a relatively low cost.