"On the pins of electrolytic capacitors, usually the longer pins are positive, and the shorter pins are negative. However, some electrolytic capacitors may have pins that do not differ in length, at which point you need to look at other markers."

The positive and negative electrodes of electrolytic capacitors can be judged by the following methods:
  1. Look at the label of the electrolytic capacitor
  Electrolytic capacitors are usually marked clearly to indicate the positive and negative electrodes. To be specific:
  Negative electrode marking: The negative electrode of the electrolytic capacitor is usually marked with a "negative sign (-)" or "black stripe" on the housing, which is generally located on one side of the capacitor, or directly marked on the pin of the capacitor.
  Positive electrode marking: The positive electrode usually has no special marking, but some capacitors will have a small dot or plus sign (+) printed on the top to distinguish it.
  2. View the pins of the electrolytic capacitor
  On the pins of electrolytic capacitors, usually the longer pins are positive, and the shorter pins are negative. However, some electrolytic capacitors may have pins that do not differ in length, at which point you need to look at other markers.
  3. Observe the capacitor shell
  The negative electrode of the electrolytic capacitor is usually the part of the shell with stripes, and the stripes indicate the direction of the negative electrode, while the positive electrode does not have these stripes.
  4. Shape and design of electrolytic capacitors
  The shell of the electrolytic capacitor is usually cylindrical, and there is usually a concave area on the negative side, or a small hole on the top of the shell, which is also to prevent the capacitor from breaking when overloaded.

In summary:
  The negative electrode usually has an identifier, such as a "-" sign, stripe, or small hole.
  The positive electrode has no negative identifier, or may only have a small dot, plus sign, etc.